High Capacity Optimised Rapid Transport (HCORT)

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Table of Contents
Designed by Ken Dawber
Email: KEN@JYPES.COM
Version 0.0.7
Date: 12th June 2017
http://HCORT.COM
http://HCORT.ORG
This proposal seeks to outline a proposed new public transportation system which will do the following:
Compared to current schemes of creating new road freeways (expressways) or creating new rail lines, this proposal seeks to perform the above while
This new transportation system has been named 'HCORT' as it is a High Capacity Optimised Rapid Transport system.
HCORT is a set of principles, concepts and ideas that advance upon Personal Rapid Transit (PRT) concepts to
create a complete design for a new transportation network. This
new transportation system will replace trains, light rail, trams
(streetcars), buses and most use of roads.
Personal Rapid Transit (PRT), called Podcars in Europe, is a controversial set of principles for transportation systems that can be summarised as follows:
Automated networks of small vehicles on express guideways
An expanded definition of PRT is given in 'USA's Official Position' in Appendix A.
Although HCORT advances the principles of PRT, it still assumes that the underlying principles of PRT are correct and that PRT takes us towards a more optimal transportation system. For this reason, the document below starts with a demonstration created by this author to show the advantages of PRT:
The
following is a demonstration of how the principles of Personal Rapid
Transport (PRT) take transportation systems towards optimal.
Lets start with current transportation types
such as 'Bus Rapid Transport' (BRT) or 'Light Rail'. With these
transport types, good transport systems can have the following
characteristics:
a) Vehicles run on a dedicated path that acts like a freeway (expressway) between stops.
b) For each stop, the vehicles determine if there is a passenger requesting that the vehicle stops, and only needs to stop for such requests. That is, if there is a passenger to pick up on the stop or if a passenger on the vehicle requests the vehicle to stop there.
When these characteristics are implemented, both of these transport types are superior to other types that don't offer it.
Now let us take a route in medium density and assume that the BRT or Light Rail ran every 10 minutes in some period.
When we look at vehicles on these transport systems we typically find them as large articulated vehicles.
What
would happen if instead of going bigger, we went the other way and made
them smaller. Lets take each of the current large vehicles and
split it into say 20 smaller mini people movers, but keep the same
number of passengers on the system.
1.Now, when passengers wait at a stop, they would only wait for up to 30 seconds rather than up to 10 minutes.
2.With the low number of passengers embarking and disembarking the
vehicles only rarely stop at any stop. Consequently, the
passengers get to their destination in less than half the time.
3.The
vehicles completes their route in less than half the time so it can go
around the route more than twice in the time the larger vehicle would
have gone around once. This means that we actually needed less
than half of those 20 vehicles to transport the same passengers.
4.The
rarity of the vehicles stopping mean that this system already uses less
energy, and as a consequence, less damaging effects to the environment.
Further changes to network to take it to PRT specifications, as
specified below will make it that the energy used is substantially less
than that of the original transport type.
Now there are obviously a few things that are not realistic with this.
1.When
a vehicle stops at a stop it would hold up those behind. This
needs to be fixed but the fact that these vehicles are very small allows
the fix for this. We can now make smaller tracks for the
vehicles. The freed up width can now be used to place sidings
along the side for the stops, leaving the main route as a full freeway (expressway), not just a freeway between stops. The overall area used by the system is still less than the original system.
2.This
is so good for the users that many people will stop using their cars
and use this public transport system. As a consequence the figures
would change drastically. In the case of public transport, this
increase in use has to be treated as a further advantage as it primarily
comes from a conversion from standard car use.
3.One
is tempted to think that the 20 vehicles would cost more than the
single large vehicle. Current costs are actually the opposite of
that. This is gone over in Appendix B 'Size Matters'.
4.Up
to recently, each of these vehicles needed drivers, which would make it
uneconomic. In effect this demonstrates that the only advantage
of the trend towards large articulated vehicles is to put drivers out of
work.
The
overall trend of technology is to automate everything and we can expect
that in time most public transport vehicles on dedicated paths will be
driverless, whether massive in size or micro. With current costs
of technology, once designed, the incremental costs of automating
additional vehicles is minor.
While the above has taken us towards PRT, it is not yet fully PRT. Other changes needed to take this to the PRT specifications are as follows:
1.PRT
changes the system methodology of passenger pickup. Instead of
vehicles travelling around scheduled routes, vehicles are simple
repositioned by a central computer to go the stop most likely needing
it. The vehicles simply wait at stops until used there or
repositioned by central control. For all times outside of peak,
when a user goes to a substation, they will almost always find a vehicle
waiting for them to take them on their journey. If a vehicle
isn't there, the user requests one and the system will send one to that
substation.
2.Travel
is point-to-point anywhere in the network in the most direct route and
without having to change vehicle. With other public transport, the
user has to go out of their way to get interconnections to achieve
travel to many destinations. For example, go into the city to get
an interconnection to a route coming back out from the city, sometimes
to a destination reasonably close to the origin. This becomes a
lot more important when the network grows to cover the city.
3.PRT
often recommends even smaller vehicles than the 20th of the large
articulated vehicle in the above analysis. Optimal sizes in terms of
minimisation of energy are normally calculated as being in 1 to 3 people
per vehicle although most PRT designs are 2 to 6 people per vehicle.
The extra size allows a family or group to stay together.
4.As
dedicated guideways for smaller vehicles are cheaper than dedicated
guideways for large vehicles, PRT principles recommend networks that are
a lot denser than that seen with BRT, Light Rail or trains.
5.The automated network makes it easy to provide a network that is available for use 24 hours a day, 7 days a week.
6.To
make BRT or Light Rail efficient in peak periods, most implementations
keep each of the stops a long distance apart as compared to standard bus
or tram stop distances. There is now no need for this.
Stops can be very close together and the system runs just as
efficiently.
The
other aspect to PRT is how dedicated automated guideways allow very
high throughput of traffic while costing only a fraction of
alternatives. This is demonstrated in a later 'Throughput Calculations' section.
The background to this is the history of Personal Rapid Transit (PRT) [11]. Since the late 1960s there has been substantial research efforts on PRT with most of this being in the 1970s and 1980s. Most of the implementation attempts ended up as very expensive failures.
How
much these failures were due to the concepts being wrong, the
immaturity of the technology of the day, politics, the efforts of those
organisations or people that would be negatively affected by this
technology, poorly managed or engineered projects or just bad luck etc.
are issues that remain hotly debated.
Much
of what is included in the concepts herein is based on the authors
research on the problems that occurred in these projects and is an
attempt to circumvent or otherwise not make the same mistakes.
Regardless
of these earlier expensive failures, along with the controversy on the
concepts, there has recently been major research studies by, or on
behalf of, the transport authorities of both the USA and Europe.
As a consequence of these studies, it can be stated that the
position of transport authorities in both the USA and Europe is that we should be directing research towards implementing PRT/ATN/podcars. Automatic Transit Networks (ATN) is another name for PRT that is being used in the USA.
Details on the findings of these studies, including a description of the main PRT/ATN/podcar concepts, is included in Appendix 1
High Capacity PRT (HCPRT) network designs are herein defined as designs suitable as primary transportation networks for a large city.
While there are a small number of PRT systems [11] that have been implemented, none can be called High Capacity PRT
and it is doubtful if any of the implemented designs would be suitable
for taking the majority of a large city's traffic as this HCORT system
is designed for.

A PRT vehicle in Masdar
City, a planned city in Abu Dhabi, in the United Arab Emirates
While the HCORT network described herein is a full and specific
transportation system, each of the individual principles, concepts and
ideas expressed herein is able to be used in other PRT/ATN/podcar
networks and similar (such as Group Rapid Transport).
One of the reasons for creating this document and getting it published was to assure that the many ideas within it are published and are therefore in the public domain.
The Central Principles of Ken Dawber's HCORT Design are as follows:
Note:
Once a major implementation occurs there will be a substantial number
of vehicles purchased. With this purchasing power, there will be a
large number of further modifications implemented such as taking away
the steering wheel and other controls etc., adding an emergency exit, particularly to the front of the vehicle.
Speeds envisaged for the system are as follows:

The current Tesla Model S electric car with a maximum speed of
249km/hr is an example of current electric car technology where the
technology of our road system hasn't kept up with the technology of the
vehicles that travel down it.
Users are able to implement virtual trailers or virtual trains, where
the users control multiple carriages throughout a journey.
Examples of this are:
HCORT is a fully automated rapid transport network
suitable for cities, towns and their interconnections which is
extremely cheap to implement and run. All vehicles are automated
driverless vehicles that run on pneumatic tyres on a near standard road
surface.
The
assumption is that all vehicles in this new transportation system are
electric vehicles and sometimes utilise two trolley poles for power.
They all have some storage of power so can go some distance
without the power lines.
It
could alternatively be implemented with standard combustion engine
vehicles or allowing a combination of both electric and combustion
engine vehicles but the proposal herein is electric.
A road that was previously a minor arterial or distributor road is converted to a new single lane each way HCORT
freeway (expressway) system. Alternatively, a pair of minor
arterial roads, possible several blocks apart, are converted to one way
single lane HCORT freeways with each being in
opposite directions, the pair together acting as a two way system.
Either way, full speed U turn lanes are provided at either end of
the HCORT freeway so that the two lanes combine to create an infinite loop.
Vehicles on this HCORT freeway
system are arranged in platoons of vehicles where groups of automated
driverless vehicles with large bumper bars are able to travel at very high freeway speeds with each touching the adjacent vehicle(s). Consequently, a single lane each way HCORT freeway system is able to handle more traffic than an ordinary ten lane road freeway/expressway.
The
freeways have embedded within them electronic guideways. The
vehicles simultaneously use multiple guideway technologies. The
area taken up by the HCORT freeway lanes is a
lot less than normal roadway lanes as the vehicles are precisely
positioned within the width of the laneway and the maximum width of
vehicles is small. The HCORT freeways are separated from the remaining area of the roadway by fences.
All vehicles on the new system have a low maximum height. At each overpass (flyovers or grade separation) the new HCORT freeways can be dug down. Beside the new HCORT freeway, the new system can provide a walkway and bikeway boulevard that the overpasses must pass over.
The characteristics of this new HCORT freeway
system is designed so that it can be implemented through out a city on
what was previously minor arterial or distributor roads with little need
for purchase of properties or compensation of the residents or
businesses residing alongside it. Use of space from major
arterials, highways and expressways would be
rare so the original transportation system is little hindered.
While many overpasses have to be created, they are of low cost due
to the low or no ramps, low span size, low pier height, high numbers to
be manufactured, ease of manufacturing offsite and lack of ability for
traffic to turn at these overpasses.
It is also possible for these high speed HCORT freeways
to be implemented on elevated flyovers. The above 'near grade'
design allows residents to drive their traditional vehicle into and out
of their properties but destroys the road's ability to handle through
traffic and stops most of the parking on the side of the road.
Where this near grade would be implemented, the increase in
transport provided by the system far outweighs the loss of traffic.
Where the loss of through traffic was considered important,
elevated flyovers can be created that allow full traffic flow
underneath. Elevated flyovers can also be used to cross over areas
where there are no current roads such as crossing over parks etc and
can be used to provide turns such as the frequent U turns that the
system needs.
Either near grade or elevated, it is possible for the HCORT freeways
to be multilane. In the case of a three lane system the middle
lane can be used to enhance throughput in the direction most needed at
any time. As the HCORT vehicles are generally not parked in the
CBD, most of the time the traffic towards and from the CBD will tend to
be symmetrical. The extra lane can also be used to provide a
branch around while a malfunctioning vehicle is being removed.
On each side of this HCORT freeway are a number of sidings.
These sidings are slow speed side branches down side streets.
Typically, these sidings go around a block or two. Each siding typically services two to six substations.
At
the substations two types of automated driverless vehicle are
available. These types are podcars (also called 'Personal Rapid
Transits' or PRT) and 'transit microbuses'. In normal use these
podcars and microbuses don't have driver controls such as steering
wheel, brake pedals or accelerator pedals.
Transit microbuses are around the size of small cars.
They are designed for shared transport but only allow a small
number of passengers and only provide simple seating. They do not
provide for any significant luggage. Even parents with prams
would be unable to use them.
At any time other than peak periods,
most substations would have several microbuses waiting for passengers.
The waiting microbuses are pre-destined to a range of
destinations. For example, a suburban substation might have a
microbus pre-destined to head towards the city and another pre-destined
to head away from the city. Typically they would pick up all their
passengers for their current journey from just one substation.
Each passenger tells the microbus which substation they wish to go
to and the microbus only stops at those substations.
Podcars
allow a user to travel in a single hop to any substation through out
the new system. They allow carriage of considerable luggage
including bikes or prams and can be used by people with walking frames,
wheel chair users and users of disability scooters. An enhanced
shopping trolley is also designed for their use.
The
provision of podcars provides better transportation service to
otherwise excluded people compared to that of the microbus system.
This along with appropriate subsidies, allows the system and the
state to fulfill its obligations.
The
substations have little infrastructure, more like bus stops than train
stations. All the vehicles they service have low floors so there's
no need for significant platforms. When users arrive, the
vehicles they'll enter will more often be there, or within a short time
of being there. Most users will be seated inside heated or air
conditioned carriages while waiting so there is only minimal seating and
shelter at substations.
The
substations will have consoles for users to make requests. If
the type of vehicle, e.g. podcar, is not waiting, then the user can
request it through a console. Similarly, if the user wants a
microbus but their destination is different to the predestinations on
the current waiting vehicles, the user can request it on a console.
A
car running on the traditional road system enters the new system
through automatic gates on a special entrance lane. Other than the
large bumper bars back and front, the car looks like a relatively
normal car with traditional pneumatic tyres but the car is an electric car. The new HCORT system senses the car and checks it out. Assuming the car passes the checks, the HCORT transportation
system takes over automatic control cutting off the ability of the
driver to control the steering, brakes and accelerator.
Under control of the HCORT transportation
system, the car withdraws it's side view mirrors and extends its
trolley poles that charge its batteries. If the car is a combined
electric and internal combustion, the combustion engine would be turned
off. Under system control the car accelerates into the freeway
and then gently pushes against the vehicle in front. A latch then
latches the two cars together.
Even
though some of these cars would be privately owned, the drivers are
able to disembark at substations. The overall system would then be
responsible for controlling this vehicle to appropriate parking and
ensure that it is fully charged. Drivers are able to use an
Internet web page or similar facility from which they can organise where
they will meet up with their vehicle.
The HCORT freeways are fenced off and all crossings such as pedestrian crossings are at a different level. Along side of the HCORT freeway
at various points along it are deceleration and acceleration lanes
needed for the exits and entrances. These are enclosed within the
same fences.
There are garden beds along side of the HCROT freeway
at various places where deceleration and acceleration lanes are not
needed. These areas have a hopefully rarely used alternative
purpose. Malfunctioning vehicles can be pushed into these areas.
This is one of the uses for the bumper bars.
There
are automatic gates between the traditional streets and the various
side streets being used for this new system. Residents who still
drive traditional cars will have special electronic controls fitted to
their vehicle. As well as giving them a control to open the gate
to their local area, it will output a signal that gives their vehicle's
position.
The
sidings may or may not be fenced, and even if fenced, the fences used
are not the strong fences used for the HCORT freeways. As well as the
sidings there are side lanes which the HCORT vehicles can travel on.
When the podcars and microbuses travel on these side streets,
particularly the unfenced ones, they do so at a slow speed.
Residents are meant to cross side streets at provided lights or
bridges but in some places there may be no barriers enforcing it.
The
residents, who still can drive on these streets, are required to follow
a set of special rules. These rules will in general mean that the
automated vehicles have right of way. Regardless of whether these
rules are followed precisely or not, there will be times when a
resident's vehicle hinders the path of an automated vehicle. The
automated vehicles have the following facilities for handling this.
1) The resident's vehicles output a signal providing their position.
The automated vehicles use this as their primary means for
collision avoidance.
2) Information from sensors at the front of the vehicles is combined
with stored information providing normal expected sensor response for
each position of the vehicle. Divergence from expected response is
used to indicate possible obstacles.
3) Central System override control can be used for collision avoidance.
This could be instigated by any of the following:
a) Sensors in the street have detected an intrusion into the path of the automated vehicles or
b) A user of an automated vehicle has pushed an emergency button or
c) A central system controller noticed a problem on their cameras.
The
operation of the automated vehicles within the side streets is referred
to as pseudo autonomous. In some respects it looks autonomous in
that they appear to mix with ordinary resident traffic but in the early
versions it is a long way from being fully autonomous. This system's
automated vehicles are following hidden electronic guideways.
Fully
autonomous would mean that the vehicles can be driven driverless in
streets that haven't been modified for them. This is a very much
safer alternative than autonomous.
As
the currently experimental autonomous vehicle technology progresses
sensors, algorithms and other parts of those systems may be incorporated
into this new system, hopefully increasing this system's speed and
safety in sidings and side lanes.
It's
also possible for factories, warehouses, shopping centres, airports and
other businesses to have a special goods entrance and exit to the new
system. Goods would be carried in automated driverless vehicles
designed for goods carriage (goodspods). The goods entrances and
exits can be from and to the lane closest to the business as the system
will have U turn facilities within it.
The
height and weight limitations means that it is not possible to carry
intermodal containers (i.e. shipping containers used for sea freight)
but the various 'unit loads' currently being standardised through out
the supply chain can be carried. Unit loads are standardised
single "units" that can be moved easily with a pallet jack or forklift
truck and are designed to pack tightly into warehouse racks, intermodal
containers, trucks, and railway goods carriages. The system can
also handle the majority, but not all, of the air cargo unit load
devices (ULD). These are standard pallets or containers used to
load luggage, freight, and mail on aircraft. Similarly, the system
would handle various other standard pallets such as the Australia
Standard Pallets so long as they were not stacked too high.
Substation
users should have access to rubbish bins, preferably different rubbish
bins for different rubbish types (recyclable etc). The system is
able to have specially designed goodspods that are able to automatically
empty these rubbish bins and take the rubbish to the appropriate
depots.
Substations
are the most convenient places to have post boxes allowing the postage
of mail and parcels. The Post Office will be able to have
automatic pick up of posted mail using specially designed goodspods.
Substations
will also have a pick up and drop off for enhanced shopping trolleys.
These trolleys are enhanced to allow large amounts of shopping to
be carried over a larger distance than traditional shopping trolleys.
Users of the system can use cards they use for fares (e.g.
identity smart cards) to access the trolleys and the system senses when
and to which substation each one has been returned. Users will
have the ability to keep them at their residence overnight and return
them to their nearest substation when they go to the substation the next
morning on their way to work.
The
system will have specially designed goodspods to automatically pick up
excess shopping trolleys from typical drop off points and take them back
to typical pick up points such as substations at supermarkets and
shopping malls.
Substations
may also have shared locked goods boxes. Specially designed
goodspods are able to deliver goods into these boxes. When local
residents or businesses order goods they provide information from their
identity smart cards. When the box delivery goodspod delivers
goods to a spare box, it provides that information to the lock on the
box. The local resident or business is then able to access the
goods at their convenience. Using their identity smart card with
the substation console, tells them which box and unlocks the box.
They can then use one of the enhanced shopping trolleys to wheel
the goods to their home or business.
Electronic
guideways can be extended throughout the area, through paths not
required for pathways to or from substations. This allows various
types of automated goodspods to service residents and businesses
directly at their premises. Automated goodspods of different types
can deliver mail, pick up various types of rubbish, pick up and deliver
goods into or from a goods box, all directly, from or to, each
individual local area business's or resident's property. Specially
designed pods may also provide a number of automated guideway or related road maintenance or roadway gardening services.
The
guideway extensions could also provide parking space for podcars which
was out of the to or from substation pathway. This could even be
into the driveway of private properties. Consequently residents or
local businesses could order podcars or goodspods to be delivered
directly to, adjacent to or close to their properties. There may
be extra charges for this, particularly when a vehicle spends excessive
time waiting for the user. Similarly, podcar or goodspod's users
would be able to direct the podcars or goodspod to one of these parking
spaces to allow users and luggage to exit the vehicle.
As
the system became heavily used, it is envisaged that the system's
pricing structure would make it attractive for the carriage of goods to
occur in off peak or night time. As well as the earlier mentioned
height limitations there would be additional limitations on maximum
axial weight to ensure that there was far less ground vibration than
occurred previous to the new system being implemented.
Previous High Capacity PRT (HCPRT) network designs have been attempted by single states or single countries. Typically
these have been funded by that state's government. A central
reason for the funding has been the attempt to make that country
dominant in the manufacture and supply of such networks.
It is the view of this author, that the world's need for this type of network should be taken at the primary reason for its design, development and test. That is, the achievement of the objectives such as the reduction of pollution
and reducing the deaths and injuries due to road accidents etc.
As such, the need for this to be designed should be treated in a
similar manner to that of reducing global pollution. That is, it
is best achieved as a cooperative effort across a large number of states
or countries.
The example of the very successful Vienna Convention and Montreal Protocol for
protection of the world's ozone layer shows that cooperative efforts
can work. Treating the job of design, development and test in this
manner is in many ways simpler and easier than that of global pollution
agreements due to the following:
A
cooperative effort by a significant proportion of the industrialised
nations will make the cost to each state or country very small. The
design itself is naturally modular. It is very easy for the
various parts to be designed, developed and tested in different
countries.
While
final implementations should not be connected to the internet, the
backbone communications system linking all the control elements will be
an Intranet that is compatible with the
internet. Consequently, for design, development and test purposes,
the internet can be used for communication purposes allowing for
example, software to run in one country controlling test vehicles in
another part of the globe.
It
is envisaged that the various states and countries that take part in
the design, will do so primarily by taking on the design, development
and test of various components, with the various transportation
authorities employing these designers. Ultimately, these designers
become the experts in this type of system so when the
state employing them ultimately implements the network, they are likely
to have less problems.
Early phases of Development should include the following:
Promote the overall concept to all states and nations. Bring into the cooperative as many as possible nations, states and other that will contribute to the development. The type of development done in this early phase is likely to include the following:
Settle
on an overall design such as the one outlined herein. Note that
designs such as this are likely to change as development progresses.
Create
initial standards and/or agreements for the various design details
needed in order to have compatible systems world wide. Following
are some examples of what this should include:
Note:
Some of these may still require research such as whether to have rare
and small power charging supply rails/catenary lines with capacitor
banks or ultracapacitors (see section on
Vehicle Design: Power) in vehicles. These details can be
changed later whenever research has shown more optimal methodology.
At least one, and preferably several of the nations involved should be creating full test tracks. A full test track will need large guideway lengths. This is expected to be greater than 100 km of guideway. The
likes of Australia with many government owned large and flat desert
like areas combined with a well educated population makes it an ideal
place to position such a test track. For reduction in costs, most
of this can be built at ground level without fences so long as there is a
method of keeping out people who might inadvertently stray in front of
vehicles travelling at 160 km/hr. Rather than the cost of test
tracks just being borne by the countries hosting them, other countries
in the cooperative should contribute to the costs. This could be
by contributing other parts such as the vehicles. The test track
will continue to have a purpose well after design completion and full
implementations exist. For example, as a way to test new versions
of software.
The
design must be built for resilience, robustness and adaptability.
This requires that the whole system doesn't stop for individual
breakdowns or non functioning parts. Major requirements for this
include:
The central control system or a number of central control systems would be used to implement the following:
Note that all of these are non critical functions. The central computers
can fall over without the overall transportation system coming to a
halt. Lower level parts of the system, particularly the vehicles,
all have alternative operational modes that are activated when the
vehicle cannot communicate to the central control or other controllers.
Automated
Vehicle Control Systems can generally be classified as 'synchronous' or
'asynchronous'. The typical implementation of synchronous system
control is to allocate equally spaced time slots to each vehicle travelling
on a guideway. Synchronous system control makes it easier to plan
a vehicle's journey and assign resources to it. Synchronous
system control is sometimes called 'clear path' as it should normally
mean that once full journey resources have been allocated, the vehicle
can complete the journey without further conflicts in allocation.
Note:
Even with synchronous control systems there can be allocation
conflicts. For example, rather than reserve a substation bay at a
final destination for a vehicle performing a long trip, this allocation
may be delayed on an expectation that one will be available. In general, parking bays are problematic due to the following:
If the expectation of an available parking bay turns out to be false then the vehicle would have to continue travelling (probably in a loop) with an offer to the vehicle occupants of alternative destinations.
In
this situation, once the vehicle arrived at the destination without
having a substation bay allocated, the vehicle is effectively in
asynchronous control. Asynchronous control systems are analogous
to the control of vehicles by human drivers. They perform their
movements without full pre-planning and adjust speeds and, in some
cases, routes as needed.
For
safety, synchronous networks needs to also be able to operate in an
asynchronous manner, either for specific vehicles that need it in
situations similar to the above or for all vehicles under emergency
conditions. Examples of other conflicts that can occur include the
following:
Both
synchronous and asynchronous controlled networks need long buffer zones
related to each merge and diverge. The buffer zones allow
vehicles to alter their speed such that they re-arrange the time they
enter the next lane.
For
turns into sidings and for re-entering the HCORT freeways from the
sidings the easiest place to add this buffering will generally be to add
length to acceleration and deceleration lanes but with sidings, the
siding itself is also used for buffering.
With
asynchronous controlled networks, regardless of having those buffer
zones, when the system becomes busy there becomes high likelihoods of
conflicts where the vehicle ends up being rerouted in sub optimal ways.
With synchronous systems, most conflicts are resolved previous to
the vehicle leaving their origin.
While we want a distributed set of individual system components such as intersection controllers and guideway controllers to operate in an autonomous manner, this can be cumbersome for the allocation of time slots or platoon positions.
For
example, assume a vehicle first gets a time slot/platoon position
assigned on the first HCORT section of its route only to discover that
when it requests a time slot on the next section or any later section of
the route, it can't get one that matches up. It now has to go
back get the initially assigned position unassigned and then attempt to
get a later time slot/platoon position. In busy periods this may repeat several times and may occur with a high proportion of vehicles. This creates many messages, is very inefficient and can end up being very slow. Vehicles
and their occupants, sitting in substation bays, would end up waiting
for this to complete before their vehicles can start their journeys.
A central control module that has knowledge of all time slots on all routes would be be far more efficient. The problem in having a central control module perform route assignments like this is that this breaks many
of our design objectives. In particular, central control needs to
be made non critical. This requires that central control modules
only enhances an otherwise running system.
To
get the best of both worlds we can have a distributed set of
intersection and/or guideway controllers performing the actual
allocations but we can have one or some additional central control
module(s) acting as route advisory module(s).
For vehicles to be assigned a route, the vehicle would normally start by sending a message to
the central advisory module. Using the data it has of the whole
network, the central advisory module would respond with a complete route
of timeslot/platoon positions. With this data, the vehicle now messages each of the distributed intersection and/or guideway controllers to get those timeslots/platoon positions allocated.
Under
various (but rare) circumstances, vehicles can go direct to the
distributed set of controllers to get their allocations. In these
circumstances the advisory module would be updated soon after so there
may be periods when the advisory module doesn't have the latest
information. Consequently, it is possible for a vehicle to be
advised of a complete route of timeslot positions where one or more of
the timeslots is not actually available.
In such a case, the vehicle would not get their requested timeslots/platoon positions allocated. Typically, in such a case, the vehicle would wait in the substation
bay until they got another suggested set of timeslot positions and
ultimately got them allocated. As this situation is rare, the odd
occurrence of it will not impact the efficient running of the network.
The route advisory module normally assumes that if it advises a vehicle of a set of timeslot positions, these will not be available for another vehicle. Another
rare occurrence that can happen is that the route advisory module can
advise a set of timeslot/platoon positions to a vehicle but the vehicle
doesn't use that data. This could occur with
someone stopping the vehicle from leaving a substation bay. In any
circumstance where a vehicle doesn't use that data, it needs to tell
that to the route advisory module.
The
control system for sidings must take into account the maximum possible
length of a vehicle. Let us assume here that this is 9 metres. Note: Such a 9
metre vehicle would need to be significantly rounded at the ends in
order to negotiate the turns being envisaged for this system and would
not be allowed in ordinary substation bays.
A
synchronous control system is easier done without the possibility of
long platoons. Since we have to allow up to something like 9
metres for the length, we could also allow platoons of 2 vehicles
latched together on sidings but only when those vehicles were 4.5 metres or less along with an assumption that the typical passenger vehicle was 4.5 metres or less long.
We
can set a time slot of 4 seconds per vehicle or pair of vehicles.
This doesn't have to match the time slots on the HCORT freeway as
there will be buffering between these guideways.
For
synchronous systems, the whole guideway does not have to have the same
speed. Various speeds can be assigned to various parts of the
guideway so long as:
For the purposes of this analysis the headway is the distance from the front of a vehicle or platoon to the front of the following vehicle or platoon.
Consequently they must be able to contain the maximum length
vehicle/platoon plus have some additional gap between the back of the
vehicle/platoon and the following vehicle. With the assigned 4
second time slots the headways at different speeds are as follows:
80 km/hr - 88.89 metres
40 km/hr - 44.44 metres
20 km/hr - 22.22 metres
10 km/hr - 11.11 metres
5 km/hr - 5.55 metres
The
first 4 of the above are all reasonable headways for automatic
controlled vehicles at the specified speed with a maximum length
vehicle. The standard assigned speeds for each section of the
siding guideway would always be 10 km/hr or more. The 10 km/hr
would be the minimum used for very sharp bends.
The last of the above at 5 km/hr(walking speed) is not reasonable, even though most of the vehicles are 4.5
metres or less long. If some situation occurs where a vehicle has
to slow down to walking speed while on the guideway, that vehicle and
vehicles coming directly behind will have to be changed from synchronous to asynchronous control.
For
example, a vehicle detects an intruder into the guideway lane such as
an animal and slows down from the assigned speed of, for example, 20
km/hr. Lets assume that the situation clears before the vehicle
had slowed below 10 km/hr. Regardless of the fact that the speed
is still within the speeds allowed for synchronous control, the vehicle
needs to be changed from synchronous to asynchronous control.
While
it can now go back up to the 20 km/hr of the section, in order to put
it back into a synchronous time slot it must now be controlled so that
it is in one of the following time slots 4, 8, 12... seconds after the
one it was in. All the following vehicles will be similarly
shifted back in time slots (by slowing them down) until there was enough
empty time slots to cover this rearrangement.
Each
of the vehicles that underwent this rearrangement of time slots would
now need the resources for the rest of their journey, to be re-assigned.
There may be a period of time where some of these vehicles don't
have assigned resources (clear path) for all their journey. They
would be partially in synchronous mode as they were now being controlled
in synchronous time slots on this guideway but they don't have clear
path through out their journey.
In
this situation these vehicles would have priority of assignment of
resources over those waiting at substations to be assigned their trip
resources.
Let
us assume that these vehicles were on the siding heading towards the
HCORT freeway. Each of these vehicle needs to be assigned a place
on the HCORT freeway before it enters the acceleration lane. If
any fails to get a place before it reaches the exit or near the exit of
the siding it will have to come to a stop and wait for an assignment.
All following vehicles will similarly have to stop behind it and
wait for re-allocation to get into the HCORT freeway.
The
vehicles do not have to be allocated clear path for all the journey in
order for them to continue onto the HCORT freeway. They only need
to be allocated a place on the HCORT freeway.
Once
they have entered the HCORT freeway without full clear path allocation
for the rest of their journey, the possibility exists that they will not
find slots to make turns into other HCORT freeways or into sidings that
would make their journey optimal. In each such case, when they
reach that turnoff without gaining an allocation they would simply
continue onwards in the HCORT freeway they are in.
The
HCORT freeways all have U turns at each end of them. This makes
each HCORT freeway an infinite loop. Once a vehicle has been
allocated to a platoon time slot on an HCORT freeway it has this place,
above all other vehicles, even above those with high priority. It
can only be re-allocated after this vehicle has been allocated a place
on an exit guideway.
Y
intersections and offshoot freeways are slightly different in the
implementation of the infinite loop. The infinite loop is
implemented to incorporate all the branches within a single infinite
loop. That is, at each of the non full cross road intersections,
the guaranteed time slot occurs when the vehicle turns in the direction
away from oncoming traffic. Note: Offshoot freeway, refers to a
Capital T junction of a bidirectional freeway where there's not a full cross road intersection.
Note
that there is a completely different control system for the side lanes
of the sidings which is mentioned in various parts of this document but
not fully detailed herein.
The
combination of platooning and variable vehicle length makes
asynchronous control systems more difficult than normal but they can be
done. For the HCORT freeways, timeslots need to be allocated to
the platoons rather than the individual vehicles. The following
provides a possible or likely analysis based on the envisaged speed of
160 km/hr for HCORT freeways.
We can set a maximum length of platoon as being, for example, 44 metres. With a typical passenger vehicle length of 4.4 metres this provides a maximum of 10 typical vehicles per platoon. At 160km/hr this maximum length requires almost 1 second to pass a point.
We
can set a time slot of 3 seconds per platoon. This very
generously provides a 2 second gap between one maximum size platoon and
the front of the next platoon at 160km/hr. A small part of this
would be used for adding vehicles into the platoon or for vehicles to exit the platoon.
Let
us now assume that at some point in the freeway we need a curve that is
too tight for the vehicles to safely travel at 160km/hr. As the
vehicles approached this curve we could reduce the speed of the vehicles
to, for example, 80 km/hr. A maximum size platoon would now take 2
seconds to pass a point and there remains, within the 3 second time
slot, a minimum 1 second gap between the back of a platoon and the front
of the following platoon.
This
demonstrates that there is significant latitude in speed. Even in
a synchronous system, the speed can be significantly changed in one
part of a freeway without affecting the speed of vehicles in another
part, allowing the system to continue in synchronous mode. The
throughput of the freeway (i.e. number of vehicles per second passing a
point) in this slower section actually remains the same as the
throughput in the faster section.
The above control example, which included the ability to slow to 80km/hr, provides for the following for each HCORT freeway lane:
maximum of 10 vehicles/platoon
1 platoon/3 seconds
10 vehicles/platoon x 20 time slots/minute x 60 minutes/hr = 12,000 vehicles/hr per lane
This
compares with a maximum of approx. 2200 vehicles/hr per lane on a
standard freeway. The HCORT lane has a maximum capacity greater
than 5 standard road freeway/expressway lanes.
There are various ways of looking at this in terms of throughput per area used.
Because
the tracking of HCORT vehicles is tightly regulated and the lanes are
restricted to only small vehicles, a pair of HCORT lanes takes up a
similar area to one standard roadway lane. Consequently, utilising the area needed for one standard roadway lane provides for the equivalent of over 10 standard freeway lanes of traffic.
An
HCORT freeway lane will have acceleration and deceleration lanes along a
large part of its length. The total width of the HCORT freeway
lane plus the acceleration or deceleration lane will be similar to the
width of one standard roadway lane. If one includes that, then the
area needed for one standard roadway lane only provides for the
equivalent of 5 standard freeway lanes for its first lane.
When adding extra HCORT freeway lanes, there
is no need for extra acceleration or deceleration lanes. Just as
with a standard road freeway/expressway, vehicles will enter the outer
most lane and only enter other lanes by merge/diverges across lanes at
freeway speed. For these extra HCORT freeway lanes, the area
needed for one standard roadway lane provides for the equivalent of over
10 standard road freeway/expressway lanes of traffic.
If
HCORT freeways were implemented such that the full speed can be
maintained throughout the freeway and the minimum gap between the end of
one platoon and beginning of the next was set to a half second (22 metres), then the maximum capacity would be double that shown in the previous example. Calculations for this are as follows:
maximum of 10 vehicles/platoon
1 platoon/1.5 seconds
10 vehicles/platoon x 40 time slots/minute x 60 minutes/hr = 24,000 vehicles/hr per lane
The HCORT lane has a maximum capacity of 10.9 standard freeway lanes. The area needed for one standard roadway lane would provide the equivalent of over 21.8 extra freeway lanes of traffic.
Should a system as specified initially, including the tight turn at 80 km/hr, run out of capacity, it could change the setup to get extra capacity using the following:
Maximum Platoon length is 88 metres
maximum of 20 vehicles/platoon
1 platoon/5 seconds
20 vehicles/platoon x 12 time slots/minute x 60 minutes/hr = 14,400 vehicles/hr per lane
The
3 second gap between the end of a maximum length platoon and the front
of the next platoon is needed in order to allow the system to slow to 80
km/hr and still have a minimum 1 second gap between platoons.
The HCORT lane has a maximum capacity greater than 6.5 standard freeway lanes. The area needed for one standard roadway lane would provide the equivalent of over 13 extra freeway lanes of traffic.
The above examples have assumed that the speed on the HCORT freeway is
160km/hr. There is no absolute reason why the speed should set at
that. It could well be significantly faster or slower.
There are advantages and disadvantages of each speed. For
example, a faster speed either requires longer acceleration lanes or
more powerful motors. The direction of vehicle technology is to
make it easier to go faster and it could well be that the system is
implemented at 200km/hr.
The following assumes 200km/hr with some bends that require the speed to decrease to 100km/hr. It
assumes that a typical HCORT vehicle is 4.0 metres long and platoons
have a maximum of 14 vehicles/platoon. This provides for maximum
platoon length of 56 metres. At 200km/hr a length of 55.55 metres
is travelled each second.
Setting
the time slot to 2.5 seconds allows the gap between platoons to
decrease to about half second when at a bend that requires the lowest
speed. This would be made reasonable by requiring that under these
circumstances it doesn't allow merges and diverges near the bend.
maximum of 14 vehicles/platoon
1 platoon/2.5 seconds
14 vehicles/platoon x 24 time slots/minute x 60 minutes/hr = 20,160 vehicles/hr per lane
The HCORT lane has a maximum capacity greater than 9 standard freeway lanes. The area needed for one standard roadway lane would provide the equivalent of over 18 extra freeway lanes of traffic.
Statistics on freeway use have shown that there is typically 1.2 people transported per vehicle on a normal freeway.
If
the new HCORT system operated only with the public transport vehicles
being for the "exclusive use of an individual or small group travelling together by choice" then the number of passengers transported per vehicle will also be close to this 1.2 per vehicle.
It
is anticipated that the public transport vehicles will be
"available for the exclusive use of an individual or small group
..." throughout day and night but have an additional option in
peak periods. Although optional, there would be substantive
incentive(s) to utilise it. For example, users that required
exclusive use in peak periods would be charged significantly higher
fares.
The additional option provides a strategy to increase the per passenger per vehicle utilisation. It will work as follows:
The
booking/request (i.e. mobile phone app or device at substation) for
vehicle system will provide the control system both the location where
the user is travelling from and the destination. The control system will try to match requests.
If
a user enters a vehicle in a peak period without a booking/request,
after the user has entered their destination, the control system will
attempt to find other users to share the vehicle. This would
include displays that showed the substations that were appropriate for
sharing this vehicle. Such displays would be on both the vehicle
and the substation bay.
When the vehicle is full or after a specific time attempting to get it full, it will perform the journey.
There
would likely be an acceptance of another passenger where that other
passenger was going to a different substation but it was in the same
direction. This may be limited to substations on the same siding
as the first passenger in the vehicle. Alternatively, it could
allow for going down different sidings in the journey. It would
limit this so that a passenger would only have to wait for the vehicle
to go down a maximum of one siding not needed for their journey.
When
passengers alight previous to the end of the vehicle's current journey,
the substation bay and/or vehicle will display where the vehicle is
going to and attempt to replace them if possible. If there were
passenger(s) immediately available it will take them but there would not
be any significant wait.
Many cities have a traffic pattern where the majority of people are heading towards the city in the morning and returning home, away from the city, in the late afternoon.
The
small substations in the outer suburbs are likely to have several bays
where one bay could be specified as for people heading towards the CBD
and one specified for people heading away from the CBD.
In
the CBD or nearest to the CBD the substations would have a large number
of bays. Most bays would be reserved for people going to specific
destinations or range of destinations.
One advantage of transport systems like this compared to standard roads is the ease in which strategies like this provide for high seat utilisation.
All
HCORT vehicles must be able to operate in reverse. The most
common uses of this are in sidings and side lanes. Typical places it may
be used are entering and leaving substation bays, entering and leaving
properties and performing 3 point U turns. Each of these places it
would be used at slow speed.
Vehicles
must also be able to travel backwards on HCORT freeways, acceleration
and deceleration lanes and sidings at a substantive speed, although this
is expected to be a lot slower than the normal HCORT freeway speed.
This is needed in the case of accidents and similar events.
For example, assume a large wind blows a roof off a house and onto an HCORT freeway guideway such that the first vehicle to encounter it
is unable to stop in time. Assume that following vehicles are
able to pull up in time but we need an ambulance for the people in the
first vehicle. Now the quickest way for the ambulance and other
emergency vehicles to arrive is for the use of an HCORT ambulance using
the HCORT freeway. The problem with that is that there may be a
number of vehicles between the last exit and the accident. These
vehicles can't forward past the house roof and smashed up vehicle.
They need to be able to back up to and into the last siding in
order to clear the way for emergency vehicles. The emergency
vehicles can then travel directly forward to the accident site.
Backing
also provides a second route to the accident site. The vehicles
just past the accident will continue unaffected and clear the guideway
after the accident. Central control can also stop any more
vehicles entering the guideway from the sidings that are just after the
accident. Once the guideway past the accident has been so cleared,
emergency vehicles can get onto that guideway past the accident and
then travel backwards to the accident. The easiest places it can
use to get onto that guideway would be simple turns or U-turns which
exit onto that guideway. It may also be possible to get onto that
guideway through a siding but that would require removing any vehicles
in the way such as putting them into substation bays, putting them into
the side lanes or getting them to exit through the HCORT freeway
guideway.
The
new system is able to handle the majority of people and goods
transport, but not all. A complete implementation for a city
could ultimately replace all trains, buses and trams as well as the
majority of road traffic.
Remaining
road traffic would generally be goods that could not meet the size
constraints such as carriage of large cranes, cherry pickers,
construction vehicles and carriage of larger items along with vehicles
and trailers leaving the city. In order to allow these to be
driven to and from where they are needed, each alternate arterial or
distributor road or every third or fourth arterial or distributor road
along with most highways and freeways will remain unhindered for their
use.
Most roads being used by the new system will still have enough room left on the road to allow these vehicles access via side lanes but in order to allow this, traditional street parking will be stopped or substantially reduced.
When
HCORT Freeway Guideways intersect with each other they will be grade
separated by elevation. That is one HCORT Freeway going over and
one going under. These freeways need methods to turn in both
directions. With traditional road freeway/expressways there are common ways of doing this such as the Clover Leaf Interchange.
While each of the different forms of free-flow interchange that traditional road freeway/expressway
use such as clover leaf could be used by HCORT interchanges, the
recommended one herein is one that is hardly ever used by standard road
freeway/expressways. This herein recommended one is the U-Turns Interchange.
Like
most interchange designs, the U-Turns Interchange has for each
direction of traffic, Simple Turn Lanes from the direction being travelled
to the direction away from opposing traffic. That is, if vehicles
of a bidirectional pair of guideways travel on the left hand side then
these are turns to the left. If they travel on the right hand
side, these are turns to the right. For the purposes of this
document, these turn lanes are called 'Simple Turn Lanes'.
The
Minimum U-Turns Interchange has two grade separated U-turn Lanes on one
of the bidirectional freeways, one in each direction. The
entrance to these U-Turn Lanes is situated after the completion of the
Simple Turn Lanes. That is, if a vehicle travels straight down the
freeway containing the U-Turns, it first passes the entrance from the
opposite direction's U-Turn Lane, then it passes the exit into the
Simple Turn Lane, then it crosses under or over the other freeway, then
it passes an entrance from the other freeway's Simple Turn Lane and
finally it reaches the entrance into the U-Turn Lane that it is able to
enter.

A diagram of the minimum
U-Turn Interchange
Using this interchange configuration, vehicles travelling
in any direction are able to make any turn including U-turns.
That is they can make a left turn, a right turn or a U-turn
regardless of which direction they were initially travelling.
All of these turns are free flow. This includes turns both
from and to the freeway that doesn't have U-Turn guideways.
Some of these turns require combining multiple turn lanes. The most complex is performing a U-turn while travelling
on the freeway that doesn't have U-turn Lanes. To do this the
vehicle makes a simple turn followed by a U-turn on the other freeway
followed by travelling to the other U-turn,
making another U-turn and then finally making a simple turn back into
(but in the opposite direction) the freeway it was in previously.
The
above Minimum U-Turns Interchange can be expanded to have pairs of
grade separated U-Turn lanes on both freeways. These extra lanes
provide full redundancy for every turn lane or the straight through
paths. That is any turn lane, or the straight path under or over
the other freeway, can be out of operation with the remaining paths
providing a route to complete any turn, including U-turn, or straight
through journey. In a 24 hour network we need this in order to
perform maintenance on the interchange lane guideways.
This
Expanded U-Turn Interchange is herein the recommend interchange to be
implemented for the intersection of HCORT Freeway Guideways. Other
advantages of this interchange include:
- It makes U-Turns easy. Other aspects of this HCORT design mean
that there will be a higher frequency of U-Turns than the other turns.
The way HCORT configurations are designed herein with one way
sidings entering the HCORT freeways mean that vehicles are often
entering in the opposite direction to that required for their journey.
A similar problem exists for vehicles exiting to sidings.
- It maintains all the intersection on just two levels (grades) and the heights between those levels.
- These U-Turns are a lot more compact than configurations such as
clover leaf. Implementation in a tear drop shape will typically
allow the U-turn lane to be implemented without requiring external
properties to be purchased.
- Maximum turns per turn lane are only 180 degrees rather than the 270
degrees of cloverleaf lane, but vehicles may have to implement more than
one turn lane to complete their change of freeway.
- The four Simple Turn Lane guideways plus four U-Turn Lane guideways
per intersection produce the possibility of production line techniques
with off-site manufacture.
- Alternative routes can be used by the central control to find a route
that has a clear-path to the destination within the various synchronous
time slots.
- The long lengths of the U-turn lane guideways provide greater
capability for buffering in order to synchronize the coming merge.
Note that the simple turns may need their length increased above
that needed for the turn in order to provide greater capability to
buffer the traffic to allow each vehicle to synchronize into the coming
merge. See below Variant U-Turn Intersection.
There
is a variant to the above described U-Turn Interchange which I call
herein the Variant U-Turn Interchange. To the freeways containing
U-turns, this variant adds a side lane from which each of the turns can
be made. This allows the order between simple turn and U-Turn to
be changed. For example, it can extend the Simple Turn Lane so
that it connects into the entrance of the U-Turn lane and allows
vehicles to enter the destination freeway after the U-Turn lane.
This
author is not aware of any road that uses the standard U-Turn
Interchange exactly as described earlier but there is one example of a
Minimum Variant U-Turn Interchange built on the Dongbu Expressway in
South Korea. This can be seen on google maps at:
https://www.google.com/maps/place/37%C2%B033'35.8%22N+127%C2%B004'19.5%22E/@37.5597444,127.0732187,16z/data=!4m5!3m4!1s0x0:0x0!8m2!3d37.55994!4d127.072071?hl=en
An
expanded version of the Variant U-Turn Interchange may be a better
option for HCORT free interchanges as it provides longer length for
buffering in order to complete synchronization of vehicles in the coming
merge of their journey.
In
the outer suburbs the HCORT freeways will go along the centre of roads
that were previously minor arterial or minor distributor roads.
Road changes required due to placing this guideway in the centre
will often involve changing the function of the road to simply being for
local traffic.
There are a number of options on how to place HCORT freeways and sidings. The main ones are as follows:
A) Place
a bidirectional pair of HCORT freeway guideway lanes in the centre of
an arterial/distributor road. This may be significantly cheaper
than options B: or C: below but this primarily depends on the cost of
the fencing and the costs associated with adding U turns. It also
depends on if there is enough room in the arterial/distributor road for
these and associated acceleration/deceleration lanes while still
providing sufficient roadway use for standard traffic such as access to
properties.
The
primary advantage of this configuration (compared to B: and C:
configurations) is that the cost to fence the pair of HCORT freeway
guideways will be similar to the cost to fence just one of the single
direction HCORT freeways and both need to be fenced. There may
also be reduced costs in having fewer but larger overpasses/underpasses
along the length of the HCORT freeway guideways. When the pair of
HCORT freeway guideways become elevated there may also be cost savings
in the pair of guideways being able to share foundations and support.
In
this configuration, sidings, both entry and exit, are expected to only
connect into the HCORT freeway guideway on the same side of the
arterial/distributor road as them. That is, they only connect into
the nearest freeway guideway, not the one in the opposing direction.
This
means that turns from the sidings into the HCORT freeways (via
acceleration lanes) will often have to be done such that the vehicles on
the HCORT freeways are going in the opposite direction to that wanted.
The vehicles would then perform a U-turn to go where they wanted.
A similar problem exists for vehicles attempting to enter a siding. Their journey will often have them travelling
on the opposing traffic freeway lane. To get to their siding they
will go past their siding, perform a U-turn then on the return to that
siding they will be able to make a simple diverge into the deceleration
lane of that siding.
Another
problem with this configuration is that it assumes that there is a
reasonable route for sidings to travel around some block or blocks of
back street, or at least it assumes it for the initial implementation.
It is preferable for it to travel around some block or blocks as
that allows the siding to be implemented as one way lanes.
This
will not always be the case and the siding will then have to be
implemented with two guideways down the back street in order to return
the traffic from the siding. It may also require the vehicles to
perform a U-turn on the siding. If the siding has very low traffic
it may be possible to implement a time multiplexed single lane with
bidirectional traffic.
Note
that this type of problem will only be a problem in the early
implementation of a city. As more HCORT freeways become
implemented such that there is another HCORT freeway one, two or three
blocks over, then some of the sidings will be converted to allow travel
across to the further away HCORT freeway.
B)
Place a single direction of HCORT freeway guideway on one
arterial/distributor road and place the opposite direction of HCORT
freeway guideway on an arterial/distributor road that is roughly
parallel but one block over.
Some
sidings would go as one way guideways in one direction between the
HCORT freeway guideways and some would go in the opposite direction.
In
the early stages of implementation, previous to there being more HCORT
freeways out to each side, there would be some sidings that travel
around some block or blocks of back street and return to the same HCORT
freeway guideway, in a manner similar to that required in A: above.
This is required for all sidings on the outside of the
bidirectional pair of HCORT freeway guideways.
The advantage (compared to A: above) are as follows:
C) Place
a single direction of HCORT freeway guideway on one
arterial/distributor road and place the opposite direction of HCORT
freeway guideway on an arterial/distributor road that is roughly
parallel but two blocks over.
The
disadvantage of this (compared to B: above) is that most of the sidings
will require crossing the in-between arterial/distributor road,
presumably by near grade underpasses.
The advantages of it (compared to B: above) are
Narrow
back streets converted to containing sidings or designed originally for
sidings will typically have the following configuration:
-
Automated vehicles designed for the new HCORT system can also go up and
down the side lanes. Reasons for them doing this could be as
follows:
- Problems with the side lanes are as follows:
Sidings
are often implemented as a loop. The HCORT vehicles go one way
away from the freeway on one side road and return to the freeway a block
or two away on another side road. This loop along with the
freeway will sometimes enclose a road (a back street) and will normally
enclose several of the side lanes. Consequently, most such loops
require there to be several bridges over the single HCORT lane.
These bridges must be able to hold the weight of all traffic able
to enter properties. The most common place where such a bridge is
required is just before or after, entry or exit to the acceleration and
deceleration lanes.
The
above design keeps the HCORT lanes (sidings and freeways) completely
separate from pedestrians or normal traffic. HCORT vehicles are
only on side lanes when there is no normal traffic. There may be
situations where it is advantageous to allow a degree of mixed traffic
but with the HCORT vehicles driving at a very slow speed. For an
HCORT vehicle to enter and exit properties it must cross a footpath and
consequently not run over any pedestrians or other footpath users.
Possible methods to allow bikes on these roads are as follows:
Initial implementation is problematic as:
The
recommended initial implementations herein tries to show off the system
under these conditions, while reducing the costs and problems of the
recommended near grade installation.
The
best initial implementation would be for the majority of resident
coverage (most of the substations) being from new outer suburbs being
built and sold at the same time as the HCORT network is initially
installed and the HCORT freeway to be able to carry these people to and
from a train station close to the CBD as well as to and from a number of
major centres. The advantages of making this the initial
implementation include the following:
The
following implementation is based on large cities of the style of
Melbourne, Australia, where the author of this submission is resident.
The characteristics of such a city are as follows:
An HCORT implementation plan for such a city would be as follows:
•The
initial implementation would be based on one or more radial HCORT
freeways that allowed passengers to go directly to an inner suburban
train station where they can get a short express train to the CBD.
These initial implementations would also connect into shopping
centres, schools, factories, hospitals, police stations, theaters and
other centres. The majority of the HCORT freeway and almost all
the outer suburban sidings would be implemented at ground level as
near-grade guideways with grade separation. As the HCORT freeway
approached the inner suburbs, it would run on an elevated track that
allowed the original use of the roads below to continue. The main
inner suburban substation would be implemented elevated on top of a
major train station.
•Initially,
most of the substation sidings would be in residential areas in the
outer suburbs, particularly the far outer suburbs. It would be
easier still if the suburbs were new suburbs, just being created as the
new system was implemented. Sidings in inner and middle suburbs
would be for access to specific shopping centres, schools, factories,
hospitals, and other major centres along with police stations.
Note that these early implementations would not connect to sports
grounds etc. that had events with large special event crowds.
•The
first HCORT freeway would extend outwards beyond the outer suburbs.
As well as having night parking for HCORT vehicles, there would be
extensive parking for standard road vehicles for those that needed to
drive to get access to the new HCORT system along with permanent parking
for vehicles owned by residents who have lost their roadside parking.
•The
next implementation would include implementing an HCORT freeway
guideway roughly parallel but one or two blocks over from the initial
implementation. Included with this implementation would be sidings
that connected to both the initial HCORT freeway and this new one.
There will be a number of sidings running in each direction.
These would be created by modifying the initial sidings as well as
by adding new ones. Once this has been implemented the
transportation network will contain alternate routes that allows
maintenance to some parts of the HCORT freeway guideways while still
allowing some journeys to complete.
•After
more radial HCORT freeway implementations as above occurred, there
would be outer and inner ring HCORT freeways connecting the radial
freeways together as a network. Until there was a reasonable
network, there would be poor network dependability as maintenance on a
HCORT freeway would bring down a large proportion of the use of the
complete system, a similar problem to that of railway lines.
•This
would first be continued throughout the radius of all the outer suburbs
not supported by train lines. The circumferential ring HCORT
freeways would cross the train lines to network the various radial HCORT
freeways. As they crossed the train lines, HCORT substations
would be created at nearby train stations.
•The earlier implementations would be extended to include sidings so that middle and inner residential suburbs had good access.
•There
would then be implementations along the train lines, Bus Rapid Transit
(BRT) and Light Rail in the outer suburbs, replacing those rail and BRT
branches. As by this time, the standard road traffic would be
reduced, the land freed up by this replacement could become bike lanes
and extra park land although some could be sold for residential use etc.
•Initial implementation within the CBD would be for goods carriages into the various businesses within the CBD.
•As
creation of substations in the CBD is after almost all the suburbs have
good HCORT access, it will involve a complete level of network
throughout the CBD. This would be at elevated levels with
substations attached to the sides of most of the large buildings
throughout the CBD.
•As or after several cities were implemented, HCORT freeways would be implemented between cities.
The
vehicles are electric vehicles powered by battery. Power for
charging the battery is provided at various places along the HCORT
freeways and while parked at substations and other parking bays. At parking bays,
inductive transfer is used. Along the HCORT freeways are short
sections of catenary lines or supply rails which the vehicles utilise
through a pair of collectors (trolley poles, small pantographs or bow
collectors). Two supply rails/lines along with two collectors are
needed due to the rubber tyres isolating the vehicle from ground.
The best place to put the supply rails/lines is likely to be below the vehicle. The
supply rails can be rails that have been set at a raised level above
the ground. That is, there is no need for the wheels to run across
them as they can always be placed away from any possible guideway merge or diverge.
Due
to the problems of skin effect when the supply is AC, it is best not to
conduct electricity through the whole rail. Rather the rail
becomes a support for a thinner electrical conductor (e.g. wire) which runs on the top or to the side of the rail. If the conductor is to the side then the electrical conductor may be below the rail's top lip. This thin electrical conductor will have insulation between it and the rail or the rail itself will be an insulator. The collectors either rub against the thin electrical conductor or rolls along it with electric conductors that collect and conduct electricity to the vehicle.
The sections of supply rails (catenary lines) on the route are turned on only when vehicles are in contact with them and all the
vehicles are at or near full speed for that section. Note that
these sections are longer than the length of a vehicle so there still is
some possibility of, for example, an animal touching the track while a
vehicle is on the track. The requirement for speed detection
ensures that the supply rails are off in the case of a major event such
as earthquake where people were being evacuated from stationary vehicles
by walking along the guideway.
These
sections of the route are all well fenced off to stop any person coming
onto the track. These sections of the route are away from overhead
crossings or any other places where a person could access them or
urinate on them as a vehicle goes past. A ground fault interrupter
switch will switch off power if any person, animal or object touches one
of the rails such that they or it conduct electricity to earth.
Ground
fault interrupters are also called 'ground fault circuit interrupters'
(GFCI) or 'Residual Current Devices' (RCD). The use of the ground fault interrupter switches requires that there is a method to return the system to normal after a ground fault interrupter switch has
been tripped. This could be manually from the central control
command station but that would require that each section of supply rail
had good video surveillance along the whole length of supply rail along
with good lighting. Alternatively it could be automatic.
Whether manual or automatic it would be better for the system to
be able to measure and monitor the current leakage to ground.
Capacitors (or ultracapacitors or
supercapacitors) in vehicles can be used to increase the energy
transfer in the sections that the vehicle collectors are in contact with
the supply rails/lines. This allows the batteries to continue
being charged from the capacitors after the vehicle has passed the short
sections of supply rails/lines.
The
main advantage of using capacitors is that the guideways can be built
with very short sections of supply rails/catenary lines and long
distances between them. A more thorough cost analysis of including
capacitors versus ultracapacitors versus not including capacitors needs to be done. The following assumes that capacitors are added.
Including
capacitors, subsystems in each vehicle to implement the collection of
power from the supply rails/catenary lines through to the charging of
the vehicle batteries, in the order or route of the energy transfer, are
likely to be as follows:
1.Pair of power collectors collects power from supply rails/catenary lines.
2.Input protection. Particularly protection from lightning strikes.
3.Intelligent
AC to DC switch mode power supply with active power factor correction.
This power supply will control or limit the output current, and
consequently the input current, to that appropriate for the system and
limit the maximum output voltage to that allowed by the capacitor bank.
4.Electronic switch(s) or diode(s) to disconnect capacitor bank from the AC to DC switch mode power supply when the vehicle is not collecting power.
5.Capacitor
bank. Additional inductor(s) and/or resistor(s) may be added to
the capacitor bank in order to create a low pass filter to protect the
capacitors from voltage spikes.
6.Intelligent DC to DC switch mode power supply converting the varying DC of the capacitor bank to the appropriate battery charging current.
7.Electronic switch(s) or diode(s) to disconnect batteries from the DC to DC switch mode power supply when the power supply is not charging the batteries.
8.Low Pass Filter (may not be needed).
9.Vehicle Batteries.
In
recent years, new types of capacitors or pseudo capacitors have come
onto the market which have a far higher capacitance per area or per
kilogram mass. These are called supercapacitors or
ultracapacitors, two names for the same thing.
The
higher capacitance means that they can store a higher amount of energy.
The problem is that they don't handle energy transfer into them
as fast as do normal capacitors although they handle it better than
batteries.
They
have slightly different properties to normal capacitors. For
example, they don't handle higher frequencies very well. With
frequency they substantially reduce their capacitance. Because of this, it is better not to use them for frequency filters.
Including ultracapacitors,
subsystems in each vehicle to implement the collection of power from
the supply rails/catenary lines through to the charging of the vehicle
batteries, in the order or route of the energy transfer, are likely to
be as follows:
1.Pair of power collectors collects power from supply rails/catenary lines.
2.Input protection. Particularly protection from lightning strikes.
3.Intelligent
AC to DC switch mode power supply with active power factor correction.
This power supply will control or limit the output current, and
consequently the input current, to that appropriate for the system and
limit the maximum output voltage to that allowed by the ultracapacitor(s).
4.Electronic switch(s) or diode(s) to disconnect ultracapacitor(s) from the AC to DC switch mode power supply when the vehicle is not collecting power.
5.Low pass filter. The capacitor(s) as part of this will be standard capacitors.
6.Ultracapacitor or ultracapacitor bank.
7.Intelligent
DC to DC switch mode power supply converting the varying DC of the
ultra capacitor(s) to the appropriate battery charging current.
8.Electronic
switch(s) or diode(s) to disconnect batteries from the DC to DC switch
mode power supply when the power supply is not charging the batteries.
9.Low Pass Filter (may not be needed).
10.Vehicle Batteries.
Another option with ultracapacitors is to use ultracapacitors without using a battery. In
that case subsystems in each vehicle to implement the collection of
power from the supply rails/catenary lines through to the charging of
the vehicle batteries, in the order or route of the energy transfer, are
likely to be as for 1 to 6 in the above subsystems.
A more thorough cost analysis of including a capacitor bank or ultracapacitor(s)
may find that the overall system is cheaper without including it in the
vehicle charging system. The main savings would be the lack of
capacitors and lack of DC to DC switch mode power supply.
Without the capacitor bank or ultracapacitors,
subsystems in each vehicle to implement the collection of power from
the supply rails/catenary lines through to the charging of the vehicle
batteries, in the order or route of the energy transfer, are likely to
be as follows:
1.Pair of power collectors collects power from supply rails/catenary lines.
2.Input protection. Particularly protection from lightning strikes.
3.Intelligent
AC to DC switch mode power supply with active power factor correction.
This power supply will control or limit the output current to the
appropriate battery charging current.
4.Electronic
switch(s) or diode(s) to disconnect batteries from the AC to DC switch
mode power supply when the vehicle is not collecting power.
5.Low Pass Filter (may not be needed).
6.Vehicle Batteries.
Without
the capacitors, the HCORT guideways would have to have longer and far
more of the supply rails/catenary lines. For example, they could
be an average of 30 metres long and occur on 20 percent of the
guideway's length.
Whether
capacitors are included or not, the above battery charging system allow
the vehicles to have very small batteries. For example, a
battery that would only power the vehicle for 10
kilometres without extra charge would probably be sufficient.
This is far smaller than that typically used in electric cars.
For dual mode vehicles
with sufficiently large batteries, the addition of this charging system
would be optional. Regardless of whether the charging system is
installed, all vehicles will need to have the state of their battery
constantly monitored along with an appropriate exit strategy if the
battery charge is below a reasonable amount.
In
countries where heating is needed, power for heating may be extracted
either directly after the input protection or directly from the
capacitor bank.
Coils
embedded within the parking bays are used to provide inductive transfer
when vehicles are parked at substations and overnight parking areas and
similar. The coils are only energised when a vehicle is parked
above it. The coils are energised with an AC voltage.
Each
parking bay monitors how much energy is supplied to each vehicle and
each vehicle monitors how much energy it receives. These details
are sent to the control system which checks that they reasonably match.
In this way, the system can recognise if there is any attempt by
local residents or others to harness the power supplied at parking bays.
Each vehicle has a power receive coil which, when the vehicle is parked in a parking bay, will be close to the coil embedded in the parking bay just below it. Both
the power receive coils in the vehicles and the power transfer coils
embedded in the parking bays are wound on appropriate cores which are
designed and arranged to provide high magnetic coupling between coils
and low energy loses.
Implementation
of the collection of power from the receive coil through to the
charging of the vehicle batteries should be able to utilise most of the
subsystems used in the above supply rails/catenary lines through to the
charging of the vehicle batteries.
The receive coil can be connected through an electronic switch to an input to the AC to DC switch mode power supply from 3. in the subsystems above. As
well as providing the appropriate AC to DC conversions, this means that
the capacitors or ultracapacitor(s) are used to continue charging the
batteries for some time after the vehicle has left the parking bay.
The
subsystems used on the HCORT freeways for collection of power from the
supply rails/catenary lines through to the charging of the capacitor
bank can be used at a very high rate of power even if designed without
large heat sinks. The reasons it can handle such a high rate of
power are as follows:
The
same conditions do not apply to the use of these subsystems for
collection of power from the parking bay coils. For this reason
the intelligent AC to DC switch mode power supply needs to recognise
when it is getting its power from the parking bay coils and control or
limit its output to a far lower current than when it is getting its
power from the power collectors collecting from supply rails/catenary
lines.
Need to assume the following:
Need
multiple methods of gaining position and track at any point of time.
Methods able to be used for position fixing and vehicle tracking:
A combination of the following:
•One
or more continuous lines of magnets may be useful as a way of backing
up the embedded wire(s) in case of loss of power to the wires.
Several of the currently designed PRT and automated bus systems use
similar magnets as their primary source of tracking. The problem
with using it as the primary source of tracking is that there is a
possibility of someone throwing some magnetised bolts or nails on the track. That is, as a modern form of placing rocks on railway lines.
•Counting
rotation of drive wheels such as counting of stepper motor steps in
order to locate distance along from the previous fix. This can be used
in conjunction with a history of the steering position. While this
data can be used for vehicle tracking, it is herein anticipated that it
would only be used as a last resort backup or as a fault detector.
This style of measurement suffers from
accumulated errors. Consequently it needs frequent resetting or
initiating at known set points.
•An inertial measurement unit (IMU) can also be used as a last resort backup or fault detector. As
with the above history of steering and drive wheels, this style of
measurement suffers from accumulated errors and consequently needs
frequent resetting or initiating at known set points.
•Radio
transmitters at various distances on both sides of each track. These
could be used to give position by triangulation, trilateration or
multilateration. Their cost and their transmit distance allows for
multiple trilaterations/Multilaterations so that some number of
transmitters can be faulty and yet there is still an accurate position
fix. Problems with using these for primary vehicle tracking
include:
~ they would stop working on loss of system power
~ they are too easily jammed
•The
radio system used for vehicle to central system communications (eg
WiFi) could double as a backup position fix in case of emergencies such
as earthquake faults, to give an approximate position. One problem
with this is that it is still subject to loss of system power.
•GPS
is too inaccurate to use as a main system. It may be used as a
last ditch backup in the case of emergency. Even to be used in
this backup, it needs to have significant corrections such as
Differential GPS (DPGS) (and/or WAAS). Specific DPGS stations for
this system may need to be implemented to get enough accuracy.
Also, an inertial measurement unit (IMU) would be used as an aid
for when GPS signals are unavailable, such as in tunnels, inside
buildings, or when electronic interference is present.
•While
a number of optical methods (including laser) are cheap and accurate,
optical methods have problems with dust, snow, hail, rain, fog, insects,
buildup of dirt, repositioning after bumps etc.
-
A mechanical or hydraulic steering system based on running tracks can
be used as a backup without creating friction by having runner wheels
that in normal operation are a short gap away from the running track.
This would only come into play when other systems failed such as
when the vehicle loses its power. That is, when a vehicle loses
all power it would be automatic that the runner wheels would lower, move
or close such that they griped or pushed against the running track.
The
lowering, moving or closing could be implemented by springs.
Holding the running wheels off the track, creating the short gap,
could be implemented by electromagnets that are normally on when the
system is running normally. A loss of power means the
electromagnets turn off, which allows the springs to push the runner
wheels to the running tracks.
The
running tracks need to be arranged so that they steered the vehicle off
the main freeways and onto sidings and off sidings onto side lanes.
In the case of vehicle power failure or some other emergencies,
the following vehicle would be able to push the failed vehicle, with
this mechanical steering system automatically directing it to the best
place. Such a system needs to continue working even when the
vehicle has a tyre blowout, including a blowout of one of the steering
wheel tyres.
-
Radar and/or Ultrasonic and/or Lidar ('light and radar') can be used
for detecting emergency situations such as people or animals on the
guideways or tree branches or roofs that have been blown on to the
guideways.
With
this system, it is expected that before full operation of each new
freeway, subsidiary extension or part thereof, vehicles are given
expected sensor input that was directly derived from sensors of previous
vehicles travelling on that part of the
route. In order to initially get the sensor input, a number of
vehicles travel the new part of the system in test mode.
Before
any new vehicle is used, or any vehicle that has had maintenance that
may have modified the placement of its sensors, the vehicle is required
to run around a test track comparing its sensor inputs to that of an
average of test vehicles. Using the differences between its inputs
and those of the test vehicles, it sets up an error map. The
error map allows it accurately correlate between what it sees on its
sensor inputs and what is expected based on sensor input previously
obtained from other vehicles via a central computer system.
-
Maintaining awareness of and history of steering position along with
counts of the rotation of drive wheels can be used as a vehicle tracking
fault sensor.
- trilateration: To get a distance for trilateration, each
receiver transmitter would return the signals (frequencies) received
from the other vehicle or some related in phase signal (such as double
or half the received frequency). The original transmitter of each
signal would compare the phase of the received signal returned back
compared to the original sent, in order to measure the distance
- Multilateration: [12] Each transmitter simply transmits its own
frequency. Pairs or groups of receivers work out the "time
difference of arrival" (TDOA) to the receivers by comparing the phase
difference of the signals received at different receivers. While
this requires more transmitters and/or receivers it is simpler to
implement and should produce a more accurate output.
This
could be something like WiFi so long as the data has sufficient
encryption to ensure that the system isn't interfered with by hacking or
similar. IEEE 802.11p [14] is an approved amendment to the
IEEE 802.11 standard to add wireless access in vehicular environments
(WAVE), a vehicular communication system. It defines enhancements to
802.11 (the basis of products marketed as Wi-Fi) required to support
Intelligent Transportation Systems (ITS) applications.
Dedicated
short-range communications (DSRC) [13] is also a possibility but it has
incompatible protocols in different parts of the world. Similarly
V2V (short for vehicle to vehicle) [15] technology is a possibility but
the channel allocation is in doubt and no spectrum has been allocated
in Australia.
For
platooning we need to gain a fast enough response to ensure a following
vehicle acts near simultaneous to the vehicle in front. For this
we need a direct vehicle to vehicle communication. While this
could be a range of communication types, it is probably best as radio.
The data has to have sufficient encryption to ensure that the
system isn't interfered with by hacking or similar. The
communication between each pair of vehicles would be setup by the
Central System before the vehicles came close enough to need it.
There needs to be a constant data stream within the communication
such that both vehicles can detect quickly if there is any break in the
communications. In the case of any break of communications, the
attempt at joining the vehicles for platooning is abandoned.
This
can also be IEEE 802.11p [14]. Presumably this would be
implemented with different channels allocated to those used for vehicle
to central system communication.
Dedicated
short-range communications (DSRC) [13] is also a possibility but it has
incompatible protocols in different parts of the world. Similarly
V2V (short for vehicle to vehicle) [15] technology is a possibility but
the channel allocation is in doubt and no spectrum has been allocated
in Australia.
Assume
vehicle loses all power when it is meant to be accelerating into the
merge on a main Freeway. How can an oncoming vehicle on the main
freeway be informed of this early enough to allow it to slow down so
that it doesn't smash into it?
The
cheapest and easiest way is to simply note that the vehicle that has
lost power has stopped communicating with the central computer and
assume that it is no longer driving the wheels. This is not
particularly good as we don't know if it is just some communications
fault and the vehicle is still able to go at full speed.
Consequently we really need a method of identifying position of
each vehicle that is independent of the vehicle having power.
Possible methods are as follows:
•Utilise
contactless smart card technology. The integrated circuits designed for
this technology are embedded into the outer surface of the vehicle.
This method has an advantage in that the card can provide more
information such as specifying the particular vehicle, specifying which
card, front, middle or back of the vehicle etc along with error checks.
•Sets
of permanent magnets are placed on the vehicle where they can be read
by system sensors. Placing multiple sets of magnets in each
vehicle, such as one in the front, one in the back and one in the middle
will reduce the number of system sensors needed. The magnets
could be placed on the side of the vehicle just below the body of the
vehicle. These magnets can be measured by a number of cheap and
easy methods such as Flux-gate magnetometer sensors, Hall effect
magnetometers, Magneto-resistive devices or inductive pick coils.
•Sets
of objects with specific magnetic properties (typically metals with
specific compositions) are placed on the vehicle where they can be read
by system sensors. The objects are read by what is effectively
miniature metal detectors. These could be single coil or double
coil sensors but at least one of the coils has to be energized.
Energization of the coil could be by continuous AC frequencies or
by pulses. The received signal can provide both distance to the
objects (by amplitude of the received signal) and an indication of
composition/magnetic properties of the objects (by phase of the received
signal). This may have problems with interference with the metal
bodies of the vehicles. This is particularly so as the system will
have different types of vehicles, most of which have a metal body with
different compositions of metal and difference configurations.
•Some
visible tags such as barcodes are placed on the vehicle and these are
read by system sensors as they pass by. This method has an
advantage in that the barcode can provide more information such as
specifying the particular vehicle, specifying which tag, front, middle
back etc along with error checks. As well as the barcode we could
have begin and end lines at the beginning and end of the tag and by
measuring the time taken for these to pass a sensor we can have an
accurate measure of the vehicles speed.
•While
such optical methods are cheap and accurate, these optical methods have
problems with dust, snow and ice, insects, buildup of dirt,
repositioning after bumps etc. If continuous maintenance is done,
the likelihood that these were not working when needed is
infinitesimally small. Note, that at any time any vehicle or any
specific tag on a vehicle goes past a sensor and that tag is not
correctly recognized, that information should be available to the system
and the system should be able to get the vehicle or system sensor
fixed. Utilizing this with continuous maintenance combined with
multiple sensors and multiple tags per vehicle should produce a very
reliable system.
(To be investigated further)
Other
sensors will be needed to be able to sense if the car is performing
correctly. In particular, there needs to be sensers for the following:
•Creates unemployment (or appears to).
Business
needs good transportation. Consequently, the overall effect of a
better transportation network is likely to be an increase in business
and consequently an increase in jobs. Unfortunately, many of the
jobs lost as part of this process are more obviously associated with the
creation of the new transportation network.
•Major threat to profits of large corporations such as the gas industry, automotive insurance and car manufacturing.
•IP Intellectual Property problems:
Creation
of patents for what is essentially obvious to those with a good
technical knowledge. The current low historical usage of the
concepts along with the complexity of a full network and the range of
types of implementation, many of which have not been implemented, means
that there is a large range of likely designs that may end up being
optimal for specific situations. Any person or corporation with a
good knowledge of current and upcoming technology trends can easily
match those trends with requirements of implementation to create patents
which in reality do little to advance our knowledge but rather tie up
and act as a deterrence to proper research. As a possible example
of this it should be noted that in 2004 the US granted a patent for the
concept of adding solar and/or wind power collection into PRT network
infrastructure (U.S. Patent 6,810,817).
Note: One of the objectives in the creation of this document is to
publish a substantial proportion of the concepts likely to be used in
implementing a High Capacity PRT/podcar network so that these concepts
become public domain.
•Regulatory
powers can produce excessive regulations that make this type of system
prohibitive and can block full systems after they have been fully
designed. This is particularly problematic as the technical
experts who produce the regulations often see these systems as a threat
to their career. That is, they don't want to be steam train
experts when no one wants new steam trains.
•Regulatory
requirements for disabled access. For example, more and more,
fire departments and other emergency service providers are requiring
elevated guideway systems, such as monorails, to be equipped with
emergency evacuation walkways, wide enough for wheelchairs.
•Change
in legal responsibility in case of accidents shifts responsibility for
accidents from the drivers to the transportation system.
While the 'Demonstration Analysis of PRT's Advantages' section in the Introduction
should have demonstrated that PRT principles will generally take a
transport system towards optimal, it should be noted that it does not do
so in all circumstances. For example, if a route such as an
airport to city link had only two substations, analysing the optimal in
that circumstance would produce the result that the larger the vehicle
or train that could be filled up, by waiting the most time allowed,
would produce the most optimal.
PRT
only becomes optimal when there are a significant number of stations
and its advantages increase with very large numbers of stations.
PRT
assumes typical traffic pattern. These typical patterns show that
there is an average of 1.2 people in each vehicle on freeway/expressways or other highway roads. This result has been repeated in many countries.
An example where this pattern was quite different was the first implementation that was roughly of this PRT type.
This was the implementation in Morgantown [16]. This town
is a University town with Campuses in different locations. In this
situation, students finish their lectures at the same time such that
groups of people all need to move to either another campus or to their
accommodation at the same time.
In
this case optimising required a larger size so it was implemented as a
Group Rapid Transit (GRT). GRT is like PRT except that the
vehicles can be designed for up to 25 people. The highly
successful Morgantown PRT [16] (it was called PRT by the implementers)
can be classed as an Optimised Rapid Transport (ORT) that met the needs
of the town of Morgantown but it doesn't meet the full requirements of
High Capacity needed for handling the traffic of large cities.
This has yet to be implemented.
It should also be
pointed out that taking extreme views on each concept does not
necessarily produce the most optimal result. For example, always
sticking to the PRT requirement that 'all trips should be just direct
origin-to-destination with no need to stop at intermediate points'.
Breaking this rule, along with breaking the 'for exclusive use of
an individual or small group travelling together by choice' rule can be used to increase efficiency.
Examine what happens if instead of the first passenger going direct to their destination, our passenger pickup strategy allows another passenger to share the vehicle, with the second passenger going to an intermediate substation on the route of the first passenger. It is fairly clear in this
instance that the total energy of getting these two passengers to their
destinations is less with them sharing than if they used different
vehicles.
This
appears to contradict the earlier findings. If the above
principle of sharing was continued with multiple destinations on the
route, and then expanded with larger vehicles to allow more sharing etc,
we would end up with the original BRT or Light Rail systems which we
showed was not optimal.
The
above sharing of route arrangements only shift us towards optimal if
kept to a small amount. Particularly, increasing vehicle size will
take us away from optimal except very specific and rare cases.
The HCORT variant of PRT described herein adds the following problems:
In
the 1970s and early 1980s there was a major (and expensive) attempt at
designing a PRT system with money from the French Government. The
PRT system (Aramis) had a similar seat optimisation to that being
suggested in this document. The government money being put into
this PRT system was at times controversial with the following being said
in their parliament:
"
Senator Wallace: "If I may say so, there's something else that
hasn't been perfected in this business. What if instead of finding her
'cronies,' as you put it, in this closed car with no driver, your
housewife runs into a couple of thugs? (I didn't say 'blacks '-be sure
to get that straight.)
Then what does she do? What happens to her then?"
Jim Johnson (at a loss for words): " Uh . . . "
Senator Wallace: " Well, I'll tell you what happens, she gets raped!
And
the rapist has all the time in the world, in this automated shell of
yours with no doors and no windows. You know what you've invented?
You've invented the rape wagon!"
[Shouting, commotion]"
Since
the 1970s technology has made major strides with the costs of audio
visual equipment being orders of magnitude cheaper and better. It
is now no longer a problem to have multiple cameras and microphones in
each vehicle along with continuous transmission to a central control and
continuous recording of the audio visual data.
It
is now also relatively easy and cheap to have these video and audio
streams monitored by computers so that people don't have to watch it
all. Computers may not yet be able to recognise all actions that
happen in the way that people can but they can recognise certain warning
signs and suggest certain audio video for the central control people to
monitor. For example, it is easy for computers to recognise that
an attempt is being made to cover over the cameras. Voice
recognition may not yet pick up all words of all people but the combination of voice recognition along with tones and/or pitch or similar that suggest a cry for help etc should not be that hard for computers to recognise and take appropriate actions.
Central
controller people will have the ability to talk to people in vehicles,
letting them know that they are being monitored and persuading them not
to do particular actions. Central Controller people will have the
ability to re-route vehicles including being able to route a vehicle to a
police station with the doors locked. This makes all HCORT
passenger vehicles potential paddy wagons rather than rape wagons.
The
sharing arrangements suggested only occur in peak periods. Peak
periods are mainly daylight hours and the above attempts at rape or
similar are more likely to occur late at night.
Any
person is able to have their own vehicle in peak periods. They
just have to pay more. People with special requirements should not
have to pay extra.
The
ability to have the new transport system drive passengers right to or
from their property provides far greater safety than that obtained from
other public transport systems. The problem with this, at least in the early implementions, is
that only a subset of passengers will have this capability. Many
of the users will be people who live in a street near to a substation
but since the system isn't in their street, they initially will only access it by walking to and from the substation. When ultimately, full autonomous vehicles are road safe and integrated into the system, they will have other options.
Regardless of earlier expensive implementation failures,
along with the controversy on the concepts, there has recently been
major research studies by, or on behalf of, the transport authorities of
both the USA and Europe. As a consequence of these studies, it
can be stated that the position of transport authorities in both USA and
Europe is that we should be directing research towards implementing
PRT/ATN/podcars.
Details on the findings of these studies, including a description of the main ATN/PRT/podcar concepts, is included below
Mineta
Transportation Institute (MTI) was originally established by Congress
and is funded by Congress, California and private grants.
What has traditionally been called PRT, they call ATN. Their report published September 2015 provides the following:
"ATN – sometimes referred to as personal rapid transit (PRT) or Podcars – is a unique transportation mode that features:
The scope of the study excludes what is called, ‘dual mode transit’, where vehicles are allowed to enter and exit the guideway."
The
study concluded that " ATN appears to have potential" ... but "More
research, development, and validation are needed" ... and that they
should "Sponsor research" ...
including
"Incentivize metropolitan planning organizations (MPOs) to develop
concepts using ATN to further sustainable transportation by issuing a
request for proposals (RFP) for ideas." etc.
The
EDICT project [2], sponsored by the European Union, conducted a study
on the feasibility of PRT. The study involved 12 research organizations,
and concluded that PRT
The
report also concluded that, despite these advantages, public
authorities will not commit to building PRT because of the risks
associated with being the first public implementation!!!
Scaling designs of some
things produce the result that the larger the better. For
example, the larger the office building the more space one obtains per
cost of building and per unit of land. Similarly, the power
obtained from a jet engine goes up more than the square of the cost of
the jet engine.
People
sometimes get used to this and expect it to continue to all things, but
there are some major examples where scaling works the opposite way.
Computer Scaling Effects:
Grosch's law or Seymour Cray rule (postulated in the 1940's) postulated that:
cost of computer systems increase with the square root of their power
By
the mid 1950s enough computers had been built to verify the law
empirically and for a while Grosch's law worked well. Then
minicomputers, microcomputers and the personal computer came along and
the law fell apart. Now, small computers often have a price per
performance ratio 100 times better than large computers. This is
the opposite to what the above law predicts.
The above is lucky for HCORT design as it will use large numbers of small computers.
The
costs this author has [10] are those locally in Australian dollars.
An Australian dollar is roughly worth about US$0.75 at current
exchange rates.
From a $600 million purchase, cost of a local train was $16m/train
(Note: limited to 90 km/h (56 mph) due to technical issues)
$32,000 per seated passenger (at 500/train)
$20,000 per passenger standing or sitting (at 800/train - a full train)
$14,000 per passenger standing or sitting (at 1100/train - a ridiculous crush/squash)
Light Rail/Trams (streetcars) had a price of $272m for 50 trams, or about $5.5m per tram.
$85,000 per seated passenger (at 64/tram)
$25,000 per passenger standing or sitting (at 214/tram)
This
needs to be compared with cars. Recently this author has hired
small cars with 'unlimited kilometres per day'. These cars were
allowed to be driven out in the country including various rough roads,
so they had many advantages compared to trains and light rail which are
very restricted. These small cars provided 5 seats each. If
these small cars were purchased by the hire company in the above multi
million dollar purchases, the cost would be well below $10,000 per vehicle and consequently less than $2000 per seated passenger.
The
ratio of cost for rail vehicle per cost of seat for a car is
staggering. Even cost of vehicle for a person standing on a light
rail vehicle is over 12 times the cost of a seat for a small car.
Buses
are approx $250,000 for a 50 seat bus. Note: I don't yet have
good figures on this. This is $5,000 per seat but cost goes up above
this as the bus gets bigger & can be lower than this with mini
buses.
In
general costs per seat go up with size of vehicle rather than the
opposite way but there are major variations to this with the smaller
light rail being more expensive per seat than trains.
Overall,
numbers of vehicles being made in the world determines technological
advancement of the vehicle type and consequently cost per seat.
Consequently buses are far cheaper than light rail, even when they are the same size.
The
above may be objected to in that the expensive vehicles will last
longer than the cheaper ones. This is more that, due to the cost
we are required to carry on using and maintaining the expensive vehicles
than that they naturally last that long. We naturally replace
cheaper vehicles earlier because it is cheap to do so. Cheap cars
are now being given five year unlimited kilometre warranties that trains
and light rail don't get.
These
HCORT vehicles are not "Autonomous" with the current usage of this
word. Rather they are automatic and driverless. Autonomous
control implies good performance under significant uncertainties in the
environment for extended periods of time and the ability to compensate
for system failures without external intervention.
In
transportation terminology, rather than autonomous, PRT is a subset of
Automated Guideway Transit (AGT) [20]. Automated guideway transit is a
fully automated, driverless, grade-separated transit system in which
vehicles are automatically guided along a "guideway".
The
HCORT design has some characteristics that are similar to the concept
of fully autonomous vehicles such as the Google car. It's similar
in that we're talking driverless automated vehicles based on standard
vehicles with rubber tyres (probably pneumatic) that are able to drive
on a flat roadway. Also, both allow privately owned vehicles to
use them as well as being able to be used for public transport.
The first six of the above
items are touted by autonomous vehicle proponents as reasons to have
autonomous, and yes, autonomous may help these, but compared to PRT,
only in a trivial way.
- Dedicated system (eg pedestrians don't walk across etc).
- Freeway/expressway guideways (Lack of stopping at stop lights etc.)
- Higher speed on dedicated guideway with all vehicles being under the same computer control.
- Safer on dedicated guideway with all vehicles being under the same computer control.
- More people converting to shared public transport.
- Conversion to electric motors.
Minimum Requirements:
Then
a significant proportion of PRT advantages could be obtained but we've
lost the fully autonomous. Interestingly, the type of central
computer control required here would make the system less autonomous
than many PRT designs.
There's
not a lot of advantage to vehicles in the early stages so getting all
vehicles to convert would be very difficult. To overcome this is
going to require that streets allocate specific lanes to the autonomous
traffic.
Continuing with changes to try to get more of the PRT advantages such as changing the dedicated streets into freeways/expressways basically continues to change the autonomous system into this HCORT system.
In
many aspects of current autonomous research, the designs are heading to
being less autonomous to overcome their limitations. For example
to advance Adaptive Cruise Control, research is heading towards
Cooperative Adaptive Cruise Control (CACC) [17].
The odd thing is that our technology is currently able to make safe HCORT transport systems across our cities (due to the reserved and dedicated guideways) but is not yet able to make safe autonomous systems (due to the 'uncertainties' requirement).
1: MTI report published September 2015 entitled:
Automated Transit Networks (ATN): A Review of the State of the Industry and Prospects for the Future
http://transweb.sjsu.edu/PDFs/research/1227-automated-transit-networks.pdf
2: EDICT Final Report (PDF) from cardiff.gov.uk
http://archive.cardiff.gov.uk/traffic/internet/jondutton/edict/current/CONTENT/Del10%20-%20Final%20Report.pdf
10:
From 2011 Auditor-General’s report into the state’s finances (page 38)
we have cost of trains and light rail/trams in Melbourne, Australia:
http://www.audit.vic.gov.au/publications/20111109-AFR/20111109-AFR.pdf
11: PRT
https://en.wikipedia.org/wiki/Personal_rapid_transit
12: Multilateration
https://en.wikipedia.org/wiki/Multilateration
13: Dedicated short-range communications (DSRC)
https://en.wikipedia.org/wiki/Dedicated_short-range_communications
14: IEEE 802.11p. A special version of Wi-Fi
https://en.wikipedia.org/wiki/IEEE_802.11p
15: V2V (short for vehicle to vehicle)
https://en.wikipedia.org/wiki/Vehicular_communication_systems
16: Morgantown PRT
https://en.wikipedia.org/wiki/Morgantown_Personal_Rapid_Transit
17:Cooperative Adaptive Cruise Control (CACC)
https://en.wikipedia.org/wiki/Cooperative_Adaptive_Cruise_Control
18: Height Adjustable Suspension
https://en.wikipedia.org/wiki/Height_adjustable_suspension
20: Automated Guideway Transit (AGT)
https://en.wikipedia.org/wiki/Automated_guideway_transit