Has everyone heard of Personal Rapid Transit (PRT)? If not, learn about it. It will soon revolutionize transit and the urban landscape. It has big implications for central business districts and of course the sky scrapers in them. No other transit system can match it.

learn about PRT at:

www.cprt.org

www.skywebexpress.com

how does this make a profit... its pretty much a driverless taxi on rails right?

I've heard about this (I think!). I believe CNN did a report on this sometime ago, it was in Minneapolis.

The groundbreaking ridership levels achieved by SkyWeb Express will generate farebox recovery ratios exceeding 150%. Expenses are lower, since automated operation removes the largest operational costs, and the system has been designed for ease of maintenance and repair. Advertising revenue increases through use of the display screen onboard. The combination of increased revenue and lower costs can result in a self-sufficient system requiring no subsidy for operations or construction.

-from the SkyWeb website

but don't take it from them. Independent studies have confirmed all this.

Yet apart from a few theme parks and demonstration systems non have been built. This concept has been hanging around since the sixties.

Yet apart from a few theme parks and demonstration systems non have been built. This concept has been hanging around since the sixties.

So there is a theme park using PRT? Which one?

PRT exists at West Virginia University:

http://www.progressiveengineer.com/PEWebBackissues2002/PEWeb%2024%20Mar%2002-2/PRT.htm

http://web.presby.edu/~jtbell/transit/Morgantown/

http://www.arc.wvu.edu/transportation/PRT.html

http://www.geocities.com/Yosemite/Forest/2137/wvuprt/wvuprt.htm

Here is my 'Personal Transit'

http://img69.photobucket.com/albums/v210/Nickkyobashi/test_047.jpg

LOL

PRT is a type of automated people mover - APM system (the one use in many airports around the world) - basically it is designed like a personal taxi but operated on a guideway. It follows concept of car pooling but works like an elevator if you know what I mean.
The idea is that each of these vehicles (which fits between 4-6 people) operates on a fixed guideway and can pick up and drop off passengers at stations along a designated route. Many experts say this form of transit is more suitable for low density cities like LA, Houston or a large building complex like university, defence compound etc. The advantage of PRT is obviously the relatively cheaper investment and operational costs (in theory anyway) compare to other form of transit such as light rail, metro. The PRT system can be designed such system to serve low density area in the suburbs, where it may not be economically feasible to build or extend a light rail, bus routes or whatever...plus you can design it so that it runs through building, university, shopping centers.

Many PRT prototypes are underdevelopment in US, Germany, France, Japan and Korea. Actually one of the leading developers of PRT is the American company Raytheon Corporation whose main expertees are in defence technology ;) I did some background research on various PRT systems for one of my uni assignment, comparing this and a Light Rail System.

There was a proposal a few years ago to build one this system in Sydney.. using slightly larger vehicles called GRT (Group Rapid Transit).
Another site to check out is Skytran Technology's - http://www.skytran.net

here's some computer renderings of their system:

http://www.skytran.net/01Homepage/Images-Homepage/SkyTran%20Seattle2%20web.JPG

http://www.skytran.net/01Homepage/Images-Homepage/SkyTran%20station%20-%20mountain%20web.JPG

its like a citywide rollercoaster ride

Its no different than a train.

A Google search turned up these skeptical links:

http://www.roadkillbill.com/PRTisaJoke.html

http://www.lightrailnow.org/facts/fa_prt001.htm

http://pulsetc.com/article.php?sid=1056

its like a citywide rollercoaster ride


PRT would be a pretty unexciting thrill ride, since it would not careen around with drastic changes in elevation or g forces.

Before anyone makes up their minds one way or another about PRT, I encourage you to review some of the literature written by people who know and understand the PRT concept. It is not like a train, nor is it like the automobile. Most of all, it is not a joke or The Jetsons. Here are some places to start reading:

http://gettherefast.org (contains direct rebuttals to skeptics linked in Post 13)
http://kinetic.seattle.wa.us/prt
http://cprt.org
http://cities21.org
http://skywebexpress.com
http://atsltd.co.uk

I'm new to this forum, I look forward to a robust and friendly exchange.

In one of the previous posts in this thread, a link is provided to the remarkable website of an organization called Light Rail Now!. If you read the Light Rail Now! article on PRT, you will see that:

1. The West Virginia University (WVU) PRT carries 16,000 riders per day when school is in session. (Actually, Light Rail Now! neglects to report this fact.)
2. The WVU PRT covers its own operating expenses.
3. The WVU PRT extends for 3.6 miles.
4. The cost to build the WVU PRT in current dollars is $89 million per mile for a fully grade separated route.
5. The WVU PRT is a FAILURE!

Light Rail Now! has also blessed us with an article concerning the new streetcar system in Tacoma, Washington. If you read the article, you will find:

1. The Tacoma streetcar carries 2,170 riders per day.
2. The Tacoma streetcar collects no fares and covers none of its operating expenses.
3. The Tacoma streetcar extends for 1.6 miles.
4. The Tacoma streetcar cost approximately $50 million per mile to build for a route that sits in the middle of a downtown street.
5. The Tacoma streetcar is a SUCCESS!

So, the WVU PRT is a failure and the Tacoma streetcar is a success. Go figure!

5. The WVU PRT is a FAILURE!


The Morgantown PRT is actually an AGT or Automated Guided Transport. It's really a variation of the familiar "people mover" you see in airports. The PRT people have disowned it, I suspect because its ugly concrete guideway and its cost overun. They also disown the Raytheon prototype PRT for much the same reasons.

PRT is really a cult:
http://www.WhatDoesItLookLike.com/images/Hum_prt_cartoon.jpg

I'm not seeing how PRT could carry significant numbers of people without major major infrastructure. This Group Rapid Transit seems much more capable though. Basically just higher frequency LRT that adapts to where people want to go and how often.

Otherwise it looks like it would end up much like a taxi rank, with a long wait for a vehicle.

The Morgantown PRT is actually an AGT or Automated Guided Transport. It's really a variation of the familiar "people mover" you see in airports. The PRT people have disowned it, I suspect because its ugly concrete guideway and its cost overun. They also disown the Raytheon prototype PRT for much the same reasons.

PRT is really a cult:
http://www.WhatDoesItLookLike.com/images/Hum_prt_cartoon.jpg

:rofl:
I like the cartoon..
I really do think the potential of PRT is worth further investigation though.. especially how such a system can be designed to integrate into an urban environment.

I'm not seeing how PRT could carry significant numbers of people without major major infrastructure. This Group Rapid Transit seems much more capable though. Basically just higher frequency LRT that adapts to where people want to go and how often.

Otherwise it looks like it would end up much like a taxi rank, with a long wait for a vehicle.

I think the main infrastructure cost would be construction of the guide rails but I know there's a system being developed in Korea at the moment where these vehicles can run on rubber wheels on roads as well as on steel rails.
yeh they should make the vehicle a bit bigger... I'd say like a minivan.

To be basically a car replacement you would need it to at least accomodate disabled people and those with some sort of luggage.

Sky Taxi is a multimodal personal automated transport (PRT + Dual Mode + other modes). It is a best solution of transport problems of cities in the near and far future. Sky Taxi will substitute cars, public transport and light trucks in city centres and suburbs.

You can download the presentation of Sky Taxi concept from the Internet:
http://members.optusnet.com.au/~sprokhorenko/skytaxi.pps
PowerPoint 2003 viewer for the presentation can be downloaded from the Microsoft’s website: http://www.microsoft.com/downloads/details.aspx?familyid=428D5727-43AB-4F24-90B7-A94784AF71A4&displaylang=en

PRT is a small automated people mover, which go to any destination on light elevated guideway. Dual Mode combines ability to go on elevated automated guideway and on conventional roads. Different projects of PRT and Dual Mode exist in the USA (were subsidized by the Federal Government), Canada, European Union (subsidized now by EU), South Africa, Norway, Russia, South Korea (subsidized now) and many other countries.

But Sky Taxi is the only viable concept. It contains some non-patented inventions and service features, which are result of the analysis of mistakes and omissions in other projects. The advantages of Sky Taxi are: beautiful cheap guideway, high speed and throughput, safety and comfort, weatherproofness, noiselessness, low electricity consumption, variety of convenient transportation modes (including several cargo modes) and variety of vehicles, adaptability to any type of city/suburb (both Hong Kong and Los Angeles!) and to any part of population. Sky Taxi is based on existing technologies only, and therefore there are no technical risks.

PRT is a small automated people mover, which go to any destination on light elevated guideway. Dual Mode combines ability to go on elevated automated guideway and on conventional roads. Different projects of PRT and Dual Mode exist in the USA (were subsidized by the Federal Government), Canada, European Union (subsidized now by EU), South Africa, Norway, Russia, South Korea (subsidized now) and many other countries.


Please name these projects and the amount of subsidy.

This proposal was planned for Cardiff in Wales. They built a test track an vehicles and seemed all for it but I think the project was recently scrapped.

http://www.atsltd.co.uk/
http://www.cities21.org/ultra/

I don't like how you can't escape exactly when you want to and how the system would still be very crowded and expensive. The real solution are little flying helicopters for one person. Hopefully over time the price will go down.
http://www.time.com/time/2001/inventions/go/infly.html

Obviously it's a futuristic project that we may have to wait a while for.

Self-navagatable transport.

Monorail like things.

I'm not seeing how PRT could carry significant numbers of people without major major infrastructure. This Group Rapid Transit seems much more capable though. Basically just higher frequency LRT that adapts to where people want to go and how often.

Otherwise it looks like it would end up much like a taxi rank, with a long wait for a vehicle.

A key to the PRT concept is that a small vehicle is light weight, therefore its guideway can be small. This small guideway is less expensive per mile because its design is simple (no moving parts), its fabrication requires fewer materials, and it requires less intensive engineering to place in the ground. Depending on the company, cost is anywhere from $1-2 million to $12-15 million per mile. Compare to light rail's $50-200 million per mile, and monorail's $100-$180 million per mile. Thus, it is affordable to build more miles of PRT.

Small vehicles are practical for mass transit. Look at cars-- the vast majority are only carrying 1-2 people, yet cars carry about 95% of passenger miles in the USA. By being on-demand, 1 PRT car can pick someone up from a station, carry them nonstop at 35-40 mph to any other station in the network, then pick up another fare. One vehicle therefore can carry a number of different fares per hour. Imagine one vehicle can make 6 trips per hour-- what could 5000 vehicles do per hour? Per day? It's multiplication, folks.

The other key is that on-demand service means that riders waste little or no time waiting in stations. Big crowds do not develop, so PRT stations can be small. The standard Skyweb Express station ( http://skywebexpress.com ) is about 30 feet long and costs less than $300,000. So you can put a lot of them in a lot of places.

I recently re-estimated a PRT system for Seattle, which is about 79 square miles. Each square mile would have 4-5 stations linked by 2 miles of guideway. The result is 158 miles of guideway and over 300 stations. At $10 million per mile, this system would cost $1.58 billion-- less than the cost of the planned 14 mile, 20-22 station monorail, and with immensely better geographic coverage and quality of service.

To be basically a car replacement you would need it to at least accomodate disabled people and those with some sort of luggage.

PRT designers realize this. The Skyweb system's vehicle and station designs are ADA compliant. If you visit their site, http://skywebexpress.com, there are photos of two people in the vehicle, one in a wheelchair. It can carry 650 lbs including baggage. Each station will have a hydraulic elevator.

The ULTra vehicle also accommodates wheelchairs. Its stations will have ramps or lifts (it's British).

I quote the group SoundPRT:

"PRT is the first transit system that treats everyone equally: no matter who you are or where you live, a city-wide PRT system provides non-stop transit, 24-7. How can it do this? Because there are 4-5 small stations per square mile, everyone is within walking distance of a station, and service is on-demand. Neighborhoods no longer have to compete for routes or service allocations, and service no longer ceases late at night."

This proposal was planned for Cardiff in Wales. They built a test track an vehicles and seemed all for it but I think the project was recently scrapped.

http://www.atsltd.co.uk/
http://www.cities21.org/ultra/


The ULTra project states it has met the technical and cost objectives of its 2003 testing program. It was certified by the UK government to carry passengers.

The reason the program has been stalled-- not scrapped-- is purely political. Although ULTra is mass transit, it is not a bus or a train, so some people with influence who like trains and buses have fought it. See:

http://icwales.icnetwork.co.uk/0750expats/expats/page.cfm?objectid=12590158&method=full&siteid=50082

http://faculty.washington.edu/jbs/itrans/Summary%20Report%20Pax%20Trials.pdf

http://icwales.icnetwork.co.uk/0100news/0200wales/page.cfm?objectid=12667041&method=full&siteid=50082

"The reason the program has been stalled-- not scrapped-- is purely political. Although ULTra is mass transit, it is not a bus or a train, so some people with influence who like trains and buses have fought it."
"The reason the program has been stalled-- not scrapped-- is purely political. Although ULTra is mass transit, it is not a bus or a train, so some people with influence who like trains and buses have fought it."


The PRT proponents always have an excuse for why their silly scheme never gets off the ground.

Another thing they like to do is invade other peoples' message boards en masse. If you are wondering where all these PRT folks are coming from, look here:

http://groups.yahoo.com/group/prt-talk/

Please name these projects and the amount of subsidy.

Those projects were bad, and they have discredited the idea of PRT. You'd better see my PowerPoint presentation (see the link in my previous posting).

You can find everything about PRT and Dual Mode here: http://faculty.washington.edu/jbs/itrans/ .

What type of energy do they run on?

"The reason the program has been stalled-- not scrapped-- is purely political. Although ULTra is mass transit, it is not a bus or a train, so some people with influence who like trains and buses have fought it."


The PRT proponents always have an excuse for why their silly scheme never gets off the ground.

Another thing they like to do is invade other peoples' message boards en masse. If you are wondering where all these PRT folks are coming from, look here:

http://groups.yahoo.com/group/prt-talk/

When they are unable to find flaws in the PRT concept, the fallback tactic of opponents seems to be to attack those who support PRT.




What type of energy do they run on?

PRT systems run on electricity, so a system itself would not emit pollution. There are currently 3 types of propulsion planned by the different companies: 1. Skyweb: linear (magnetic) motor for propulsion and braking; 2. ULTra and MicroRail: rotary (electric motor turns wheels); 3. SkyTran: passive maglev system called Inductrak.


References: Linear motor explained,
http://www.force.co.uk/page2.html#WHAT

Inductrak,
http://www.llnl.gov/str/Post.html

In urban areas, PRT is more convienent than mass transit. But with so many low capacity vehicles running around, the system would become very congested just like cars on roadways. The energy usage would also be very high compared with mass transit.
Few people would use it in the suburbs, as cars would just be more convienent.
Are there any ridership models/traffic flow simulation data available to prove me wrong?

In urban areas, PRT is more convienent than mass transit. But with so many low capacity vehicles running around, the system would become very congested just like cars on roadways. The energy usage would also be very high compared with mass transit.
Few people would use it in the suburbs, as cars would just be more convienent.
Are there any ridership models/traffic flow simulation data available to prove me wrong?

Supporters are not prescribing PRT for all communities. For example, in a city with little congestion and a fast bus system with frequent service, PRT would be good but not superior-- nor would conventional rail.

The maximum vehicles/time on PRT guideway depends on the length of the vehicle, average speed and minimum headway (space between vehicles, in seconds). With a speed of 40mph and headway of 1 sec (58.6 ft), and a 10 ft long vehicle, the mathematical maximum # vehicles passing a point on the guideway is 76.9 per minute (4614 per hour).

Furthermore, unlike cars on a road, each PRT vehicle can be reused by many different riders one after the other, many times per hour. Thus, the 4614 per hour would also include multiple trips made by the same vehicle.

Because PRT guideway is configured in a network, vehicles take different routes between different origins and destinations-- vehicles are not confined to exactly the same tracks, as in a train corridor. 4614 vehicles per hour thus would represent a "point maximum", not a network maximum. In a previous post I mentioned a theoretical network with about 160 miles of guideway. It is obvious that it would be very difficult to max-out a system having that much mileage.

The system couldn't be maxed-out in reality, because the number of vehicles is set. Suppose you had a PRT fleet of 5000 vehicles on a 160 mile system, and the average journey was 5 miles at 40 mph. Each journey would take 7.5 minutes; add 45 sec at each end to board and unboard passengers, for a total time of 9 minutes per journey. Each vehicle therefore could make 6.7 such trips per hour. Thus, 5000 vehicles could make 33,500 trips per hour.

Is this enough? Consider that bus ridership in King County, Washington averages 13,000-14,000 per hour.

The other opportunity for congestion in a PRT system is in the stations.
The question is, can the stations handle the passenger throughput?

Here's what happens if you want to ride on PRT. You walk to a station; select a destination from an ATM-type machine, pay, get a ticket. It is possible you could already have a card pre-programmed with favorite destinations. Service is on-demand, so a car is usually waiting. You swipe your ticket or card through a reader, the door opens, you get in, sit down, press a Go button, the door closes, you depart. All of this does not take very long; once you select your destination, boarding probably take 15-20 seconds. When you get to your destination, the door opens and you get out.

At 15-20 seconds, a single station berth can handle 3 arrivals or departures per minute, or 180 per hour. Most stations would probably be 3 berths, or 540 per hour. In busy places (office buildings, malls, schools, arenas) there could be up to 12 or 15 berths per station (15 berths is 2700 arrivals or departures per hour). In a 160 mile network with 360 stations with an average of 4 berths each (1440 total berths), the mathematical maximum throughput is 4320 arrivals or departures per minute, or a theoretical 259,200 per hour. This is far more than the demands that could be placed on the system by a 1000, 5000 or even 10,000 vehicle system.

Regarding energy consumption, PRT systems would actually use less energy per passenger than conventional transit. This is because service is on demand, PRT cars move only when someone needs them. Trains and buses must make their scheduled runs with empty seats-- even when they are all empty.

Makers of the Skyweb Express PRT system (http://skywebexpress.com) have done many simulations for prospective clients. There may be some studies on their websites, and I'm sure someone there could provide more information by email. See also the http://skyloop.org organization for an example involving Cincinatti and the old baseball stadium. Skyweb and ULTra http://atsltd.co.uk also have information on their sites about energy usage.

The problem that I can see is that the cars have to load/unload single file. Unlike a taxi rank, where each vehicle can move out individually as they finish boarding, the cars behind cannot move until the cars ahead are ready to go. This would then block the arriving cars, which starts to line up behind the station, then out to the main guideway, then...
Just imagine a city where everyone travels by taxi, but all the roads are exactly one lane wide and there is no passing allowed anywhere......

there is a separate rail just for the station, the other cars bypass teh station on another rail

ie

<---(rail)------------------------------------>
\--------(station)---------/

but there is a disadvantage if only 1 car can unload at a time...
also the card system will be good, get in and out of the car faster, i also like system if some-one is pranking the car will be redirected to the police station.

i personally like this thing being built, but it may cost a fair amount with all the stations and high tech stuff...

there is a separate rail just for the station, the other cars bypass teh station on another rail

ie

<---(rail)------------------------------------>
\--------(station)---------/


I understand that the stations are built off mainline spurs. I'm saying that when cars queue up on the spur it will eventually back up onto the mainline. The cars won't actually need to physically be lined up out the spur for traffic jams to occur. 235 ft was quoted as the space needed to decelerate and accelerate in order not to interfere with the 40 mph cars on the mainline. Any time the space remaining on the spur line is less than this, the cars will need to start decelerating out on the mainline, slowing the main traffic flow.

Mr. Grant, you "demonstrated" system capacity by assuming traffic always flows smoothly at 40 mph. With so many stations and complicated flow patterns, local capacity can be exceeded at various choke points (such as stations) and jam up.

The station flow rates also seem a little optimistic. 15-20 sounds reasonable for loading/unloading, but it also takes time for the cars to decelerate in/accelerate out of a berth. It will take, at best, 10 seconds for the next car in queue to pull into position and be ready for boarding after the departure of the previous car. As station lengths increase, it would take even longer for the cars queing at the end to pull into position, further decreasing station flow rate.

One big crowd who's cars arrive at a station at close to the same time (rush hour traffic) would be all it takes to creat a traffic jam at the station and the surrounding area.

The reports I read at the websites provided did not address local flow either, but merely system averages, which doesn't adaquately reflect real flow at peak times.

The system seems to have very little margin for overflow - it still appears to me it is very easy to jam up, because of its combination of lots of little vehicles on random schedules competing for space on a restrictive and inflexible guideway(s).

sorry i didn't notice that ! but i agree with you now.

Hi Alabamaken, Syd-Hk;

Since Mr_Grant seems to have taken a week off, perhaps I can help explain the station dynamics some. I have co-founded a PRT advocacy organization (www.acprt.org) and have spent way too much time studying the Taxi 2000 station design and simulation programs. Please pardon me if the explanation seems a bit long - I will try to as concise as possible.


You are right about the queue challenge - If the queued cars back up too far, they would block up the mainline guideway. There are two design responses to this problem that the system implements.

1. The stations are sized to meet the anticipated rush-hour flows so that vehicles can be handled as fast as needed to avoid over-filling the queuing area.

2. In the event that the queue area is full when another vehicle needs to enter the station - it is commanded to 'wave-off' - continue down the mainline and use the first available chance to loop back around to try again. Since the PRT system is laid out as a set of inter-connecting loops, the vehicle can return to the station within a few minutes.

In the Taxi 2000 design, each station has a queuing area on the spur between the deceleration area and immediately before the station berths. This allows vehicles to decelerate, then pause in the queue while the cars in the station load and unload. Since the deceleration area must be kept clear, no vehicles are allowed to enter the siding guideway when the queue area is full.

Before discussing the wave-offs more, I would like to describe the station dynamics that I have observed from the station simulators. For this example, imagine a five-berth station with a queuing area for five vehicles. We can number the berths (from downstream to upstream) as B1-B5 and the queue spots as Q1-Q5. Let's start with all the berths being empty and the queue spots all have vehicle waiting.

Alabamaken points out the it will take about 10 seconds for a vehicle to pull into the berthing spot prior to unloading. This is reasonable, but remember that the vehicles can be moving simultaneously. So in our example, the vehicle in Q1 will pull up to B1, taking about 10 seconds. But the car in Q2 doesn't wait for the first car to finish, it can start moving just after the first one does. So it moves Q2 ---> B2, taking about 10 seconds but starting a second after car 1 does. Cars 3 - 5 do the same, each takes the same 10 seconds to move (since they are going the same distance), but starting about a second after each other. So in this example, five cars will move into position, with the last one starting to unload after 15 seconds.

This last car is the one that generally determines the minimum time the process takes. Since it started loading/unloading last, it tends to be the last one left. If a car in front of it in the berths takes a little longer to load or move out of the station, it simply waits a few extra seconds before moving forward and allowing other cars to enter the berthing area.

While the 5 cars are loading, any cars coming into the station will be pausing in the queue area, waiting their turn to move into the station and unload. So what you see in the simulations is that as the station traffic approaches the design max for the station, cars enter the siding at random times, aggregate in the queuing spots, and move in batches into the station to unload. The cars tend to complete loading in roughly the same order as they entered, since that is the order they stopped. As they finish, each one moves as far forward as it can, with the first in line accelerating up the siding and merging onto the main guideway as it gets a chance. Then the cycle repeats.

So, for this example, the last car takes 15 seconds to move into position and another 10-15 seconds of loading time before moving forward. If we round the total up to 30 seconds, then we have two batches of five cars every minute - or 600 vehicles/hour.


Now, about the station sizing and wave-offs. One of the strong points of PRT (IMO) is that the stations can vary in size from a general minimum of three to a max of around twelve or fifteen berths. The main way to minimize wave-offs is to correctly estimate the requirements and make sure the station and queuing area is sized correctly. Taxi 2000 has suggested the queue contain a number berths equal to the number of station berths, plus an additional one or two spots and that they can hold the number of wave-offs to about 1 in every 10,000 trips.

You can decrease the chances of a wave-off occurring by extending the station queue area or increasing the number of berths, but there is always a chance, no matter how large the station, that some combination of arrivals and departure delays will overflow the queue - so it becomes a cost/benefit and policy decision when deciding how much to spend and where an acceptable level of wave-offs lay.

The likelihood of occurrence and the cost, in extra-trip time, to riders that suffer a wave-off can be compared to the effects of traditional transit bus or rail running late, having mechanical problems, or otherwise suffering a delay. A one-chance in ten thousand doesn't seem too bad when compared to the on-time performance of our bus-based systems.

The extra trip time is also affected by the guideway layout. In areas with a dense network, the time will be shorter than areas with fewer, larger guideway loops. The transit agency my choose to adjust the station size to minimize wave-offs from stations that would incur the greatest time delay.




Chris J. Burr, Co-Founder
Austin Citizens for Personal Rapid Transit
www.acprt.org - chris@acprt.org

In one of the previous posts in this thread, a link is provided to the remarkable website of an organization called Light Rail Now!. If you read the Light Rail Now! article on PRT, you will see that:

1. The West Virginia University (WVU) PRT carries 16,000 riders per day when school is in session. (Actually, Light Rail Now! neglects to report this fact.)
2. The WVU PRT covers its own operating expenses.
3. The WVU PRT extends for 3.6 miles.
4. The cost to build the WVU PRT in current dollars is $89 million per mile for a fully grade separated route.
5. The WVU PRT is a FAILURE!

Light Rail Now! has also blessed us with an article concerning the new streetcar system in Tacoma, Washington. If you read the article, you will find:

1. The Tacoma streetcar carries 2,170 riders per day.
2. The Tacoma streetcar collects no fares and covers none of its operating expenses.
3. The Tacoma streetcar extends for 1.6 miles.
4. The Tacoma streetcar cost approximately $50 million per mile to build for a route that sits in the middle of a downtown street.
5. The Tacoma streetcar is a SUCCESS!

So, the WVU PRT is a failure and the Tacoma streetcar is a success. Go figure!


I know most of us here only consider it a success because it greatly exceeded ridership projections. Of course, Sound Transit used this "success" as reason to build a crappy light rail system here in Seattle that won't really go anywhere.

I never was a fan of PRT. It always seemed like a pie in the sky dream, that has no application in the real world. I can't think of one city that has seriously implemented a PRT system. That's not to say there are no PRT systems...I mean there was this one college town (can't remember name) that implement a limited PRT system but the project was so costly that it ended up being a white elephant.

light rail shares the road with road traffic and can be very space consuming in areas where land is needed. but light rail isnt bad for cities with low density like melebourne

Many PRT advocates refer to the West Virginia University (WVU) PRT as a Group Rapid Transit (GRT) or Automated Guideway Transport (AGT) rather than a true PRT system. It does share the characteristic of PRT that riders can program their own destination and skip intermediate stops; however, the cars are much larger than those featured in most PRT concept designs. The WVU cars can seat eight and can accommodate several more riders standing. Most PRT concept designs can accommodate no more than four passengers. I guess a family of five would be out of luck.

The following are some pictures of the WVU system:

http://webpages.charter.net/g.vassilakos/wvuprt/image001.jpg

http://webpages.charter.net/g.vassilakos/wvuprt/image002.jpg

http://webpages.charter.net/g.vassilakos/wvuprt/image004.jpg

http://webpages.charter.net/g.vassilakos/wvuprt/image006.jpg

http://webpages.charter.net/g.vassilakos/wvuprt/image007.jpg

http://webpages.charter.net/g.vassilakos/wvuprt/image010.jpg

http://webpages.charter.net/g.vassilakos/wvuprt/image009.jpg

The plaque reads, "In honor of, Earle T. Andrews, Board of Regents, 1969 – 1979, In Appreciation of his Dedication and Leadership in the Development of West Virginia University’s Personal Rapid Transit (PRT), the World’s First Automated Urban Transportation System, October 15, 1993, College of Engineering".


The following is an article on the system from the "Progressive Engineer":

http://www.progressiveengineer.com/PEWebBackissues2002/PEWeb%2024%20Mar%2002-2/PRT.htm

Still in a Class of Its Own

Since the 1970s, Morgantown's Personal Rapid Transit system has shuttled millions of students between campuses at West Virginia University. It still ranks as a model computerized mass transit system.

By Tom Gibson

After exiting Interstate-68 and driving into Morgantown, West Virginia, it doesn't take long to get a feel for the area's unique terrain. The Monongahela River snakes through town, and that's about the only flat feature. Rugged hills rise from the river banks, and streets wind through them taking convoluted paths.

I make my way to the Friend's Inn between West Virginia University's Evansdale Campus and Medical Center Campus, both on a plateau overlooking Morgantown and the river. Morgantown's Personal Rapid Transit (PRT) system passes in front of the hotel, offering a strange juxtaposition. The track and steel structure are rusty and drab, the concrete discolored and streaked, each showing years of use. But then, colorful and modern-looking blue and yellow cars, each the size of a small delivery van, cruise by silently. They have no drivers (and sometimes no passengers) in them.

Over a quarter century old, the PRT system ranks as the first fully-automated rapid transit system in the world. Amazingly, in an age where mass transit systems advance in technology about as slowly as airplanes (we still fly B-52s), it's still on the cutting edge. The computerized system connects downtown Morgantown and WVU's main downtown campus with the Evansdale Campus and the Robert C. Byrd Health Sciences Campus, providing transportation for WVU's 19,000 students and 7500 employees as well as community residents. In the process, it helps tame the hilly terrain.

Expansion Brings Traffic
As Bob Hendershot, systems engineering manager for the PRT system, tells it, the original idea for the system came from Dr. Sammy Elias, then-chairman of WVU's industrial engineering department. "By the late 1960s, this university had gone through a growth spurt," Hendershot relates. It originally had been located entirely downtown, but increasing enrollment dictated expanding to the Evansdale Campus, about a mile from the main campus. Several new buildings, such as the college of engineering, college of creative arts, and college of agriculture and forestry took shape there along with a large dormitory complex, and the medical center complex was built further up the hill. "Great idea, but the terrain of Morgantown and having only two roads connecting these two areas brought severe traffic problems."

WVU operated buses to shuttle students back and forth, but this only made matters worse. Jim Hatcher, systems programmer and computer engineer for the PRT system, recalls, "In the early 70s, we would actually achieve total gridlock." Hendershot adds, "At one point, the university had to not allow students to take classes at different campuses. Even in a 20-minute class change, there was no way to get to class on time."

Although an industrial engineer, Elias was more of a transportation specialist and had an interest in fully-automated transit systems. He garnered a Housing and Urban Development grant in 1969 to study the feasibility study of a system connecting the campuses. The Department of Transportation established the Urban Mass Transportation Administration (UMTA) in 1970 with a mission to explore, implement, and demonstrate new technology in transportation. Hendershot says, "Having already taken steps in this area, WVU wound up being in the right place at the right time." WVU secured a grant from UMTA to continue studying the concept and accept formal proposals for it. Several major companies submitted them.

Then came real paydirt. WVU got a grant to implement a system as a research demonstration project, being selected over other proposals largely because "a college campus was a good location to demonstrate a system like this," as Hendershot explains. "We have a captive audience. We require the students to use the system to get back and forth. We wound up having peak periods of demand every hour versus seven in the morning and five in the evening like in a city. Morgantown has the extremes of environment to test the system, from warm summers to winters with extreme cold. It's hilly area around here. The system experiences pretty much all the demands that can be placed on it. We were judged a very good test bed for a system."

Hendershot says the system mushroomed from its original design and cost estimates. "Every conceivable thing was put into it. The biggest improvement was the onboard switching capability of our vehicles, which allows stations to be bypassed. This allows direct origin-to-destination travel."

They selected a proposal submitted by Alden Self Transit, a small company in Boston. This was for a small circular test track and one vehicle, but it was the one system that featured the onboard switching capability, which formed the crux of what became known as personal rapid transit. Alden wasn't established well enough to carry out such a large-scale project, so contracts for system design went to the Jet Propulsion Laboratory (JPL). But JPL became more enamored with projects like sending a man to the moon, and they decided not to pursue it. Boeing Aerospace Company came along and obtained rights from Alden, taking over design of the system. Frederick R. Harris, a civil and transportation engineering firm in Fairfax, Virginia, served as the prime contractor for the guideway and stations. The project was built in two phases, the first coming on line in 1975 and the second in 1979.

Five stations comprise the PRT system, with the Walnut Street station at the downtown end and the Medical Center station at the other end and Beechurst, Engineering, and Towers stations in between. The circuitous guideway covers 3.6 miles between the two end stations.

Smooth and Easy
After walking a quarter mile to the Medical Center station, I embarked on a ride to the Walnut Street station downtown in search of dinner. Even as a neophyte, I found the system easy to use; you climb or descend stairs to a loading platform, insert coins in a turnstile, punch a button for the station you want, go to a loading gate, and follow directions on a sign overhead. All trips cost 50 cents for the uninitiated, but locals swipe a pass card through the machine. Soon, a car rolls into the station and eases to a stop.

My vehicle passes the Evansdale campus and then heads down a 10% grade toward the Monongahela River. Riding in a concrete trough this steep gave the feeling of riding on a luge track without the banks. After 15 minutes, I arrive at the Walnut Street station and then proceed to High Street, the main street in the business district.

Later, Jim Hatcher showed me the nerve center where computers control the system. Three people sat at control panels working in a deliberate, almost casual fashion. "This is the way we like to see it," Hatcher remarks. He explains that they operate in a form of the hours-of-boredom-interrupted-by-a-few-minutes-of-sheer-excitement mode. A lighted overhead schematic diagram shows locations of cars in the system. They were watching customers on closed-circuit TV cameras. "Our concern is not security. Our prime concern is safety." They watch for people getting into the guideway and in harm's way. They can stop a car in the area if something happens.

Ongoing Engineering Work
You might think all this is a product of the modern microprocessor age. But Hendershot says that though the system has changed since it was first built, "it hasn't to the extent one might think." For example, "Three years ago we upgraded our computer control system, but not because it didn't work. Up until 1997 or 1998, we operated with computer equipment that was installed back in 1971 and was still doing the job as it should. Maintainability was our only problem with it -- being able to buy spare parts. We have modernized a lot of the equipment over the years, but the system itself operates almost in identical fashion to when it was first installed."

"I've been here almost since day one," Hendershot reveals in detailing his history with the PRT system. He came to WVU in 1972 to get his master's degree after getting a B.S. from Ohio State in industrial engineering. "I really wasn't aiming toward a career in the transportation field." After receiving a graduate assistantship to research the software aspects of the system, "I got very interested in it. I worked here initially during the test and checkout of the software, and I've worked on every aspect of the system since then."

Besides Hendershot and Hatcher, the technical PRT staff includes a mechanical and civil engineer, two electrical engineers, and a host of technicians. Many have put in 20-plus years, resulting in a deep base of knowledge. "I think one reason people stay is that we're challenged by all the problems you could possibly imagine. You're never bored with doing the same task over and over. It really goes the full gamut," Hendershot says. Hatcher reinforces that: "This is a machine that's eight miles long and has thousands of parts. It's like a big video game."

The PRT staff usually has a few major engineering projects in progress, and they like to involve WVU engineering students in them. They assign year-long senior design projects to groups of three or four students, and graduate research assistants also work on various aspects of the system.

So how well has the PRT system worked as a research and demonstration project? When school is in session, 55 vehicles transport about 16,000 passengers a day, resulting in the system's 73 vehicles traveling about 1.56 million miles a year. With such a prolific track record, Hendershot says outsiders come in to see the system "all the time." They're mostly from cities and colleges that started with one metropolitan campus and expanded. "This type of system is really good for certain applications."

Some transportation experts don't consider the system truly PRT since the vehicles carry many people, and not all rides are non-stop from origin to destination. They label it a Group Rapid Transit system but also point out that it's the closest to a true PRT system the U.S. has seen.

In driving through Morgantown, traffic bustles in town, and it seems to have the same congestion problems as other thriving communities. But Hatcher says traffic has improved with the PRT system. "It has really helped traffic much more than the local people understand." He knows it would be a lot worse without the blue and yellow cars shuttling back and forth between campuses smoothly over the rugged terrain, as they have since the mid 1970s. It's only a matter of time until other colleges and towns copy the system.

Technical Lowdown on the PRT System
The system has 8.65 miles of guideway, which consists of a concrete running surface with sides on it. Cars travel both ways along a parallel set of tracks, turning around on loops at the ends of the track or at the stations in the middle. The guideway goes overhead on concrete piers about 20 feet high.

The vehicles run off 575-volt AC three-phase power, rectified and controlled to power the 70-horsepower DC motor that drives the rear wheels of each vehicle. A power collector mounted on the front wheel spindle of the vehicle rides on a power rail running along the guideway. Power is transferred by sprung sintered carbon/copper brushes.

Each car can carry eight seated and 12 standing passengers. Average speed of the vehicles is 14 mph, and top speed is 30 mph.

Every vehicle has a guide wheel on each side. A wheel on one side follows a guide rail in the guideway; the wheels are oversteered a half degree so they follow that side in a concept known as curb following. Both front and rear wheels steer. The steering is switched from one side to the other hydraulically to steer the vehicle. Having no physical connection with the guideway allows onboard switching, meaning when it comes to an intersection, the vehicle can follow one of two paths without the guideway itself having to physically switch and guide the vehicle.

The central control room has dual computers that automatically send cars to stations where they're needed and otherwise control them. System operators control the system during initialization, failure, or shutdown, but at other times, they merely monitor operation. Onboard vehicle computers receive instructions through two antennae by means of frequency shift key digital signals sent through inductive wire loops embedded in the guideway surface. An odometer and tachometer in each vehicle measure distance traveled and speed, supplying data to the computers. A control unit controls brakes, steering, doors, and propulsion. Four-wheel disc brakes on the vehicles are hydraulically operated in response to input commands.

By day, or in periods of high passenger demand, the system operates in demand mode, with vehicles dispatched in response to passenger requests. At night, or in periods of low demand, the system operates in schedule mode, with vehicles dispatched on a preset schedule. Vehicles are assigned to groups of passengers based on the number of people waiting for a particular destination and the length of time they've been waiting.

Each station houses control and communications equipment, including dual computers, required for controlling vehicle operations within the station area.

The guideway surface is heated in winter to remove snow and ice so vehicle tires don't slip. This can cause a collision, and wheel slippage can throw off the tachometer pulses that indicate the vehicle's speed. A heated water-propylene-glycol solution circulates through pipes embedded in the running surface. Four boiler plants along the route supply pressurized fluid using a system of pumps and expansion tanks charged with nitrogen.

Steve Raney and Stan Young will be (separately) speaking at the Transportation Research Board (TRB) meeting in Washington DC on the subject of Morgantown transit this January. People with an interest in promoting more advanced systems than buses and light rail might be interested in joining the Advanced Transit Association. Our web site is at http://www.advancedtransit.org/.

Cardiff's ULTra system is still on track - the actual vehicles are being manufactured already and the route is currently being cleared

http://www.cities21.org/ultra/Stg0_1map2.jpg

http://www.cities21.org/ultra/Vehgrade2.jpg

Many PRT advocates refer to the West Virginia University (WVU) PRT as a Group Rapid Transit (GRT) or Automated Guideway Transport (AGT) rather than a true PRT system. It does share the characteristic of PRT that riders can program their own destination and skip intermediate stops; however, the cars are much larger than those featured in most PRT concept designs. The WVU cars can seat eight and can accommodate several more riders standing. Most PRT concept designs can accommodate no more than four passengers. I guess a family of five would be out of luck.


After reading up on the pros and cons, I've decided I'm in the pro camp. I think the idea of seating just three or four is a good idea. Okay, a family of five would have to split up and use two cabs, but on the other hand, if the cabs are big, it just means them being emptier most of the time. With the WVU system, it probably doesn't matter much, because there are only a few stations, and students on a campus move around in groups a lot, anyway, but in a citywide network, with dozens or hundreds of stations, a commuter will not want to wait around for nine other people going in the same direction, just in order to fill the cab. That's what scheduled trains and buses force people to do. Why are you stuck standing in the rain waiting for a train or a bus? Because the operator doesn't want to drive it empty, so they give passengers enough time to build up in numbers. Even then, they are nearly empty most of the time. So there's a benefit to building the cabs small. On top of that, the bigger you build the cabs, the more expensive the guideway gets, so you wind up wasting money on unnecessary infrastructure, as well. It looks as if that did happen to the WVU system. The guideway is huge, partly because the vehicles are bigger than they need to be, and partly because it uses air cushion technology, which was cool at the time, but doesn't have anything to do with PRT as such.

PRT is like a taxi where the driver knows the way, doesn't get stuck in traffic, and doesn't lie to the operator about his whereabouts. In fact, it doesn't have a driver, so once it is up and running, it's cheaper even than a bus. (That's the claim, and when I look at the detail behind it, I find it to be a credible claim.) All previous attempts to build a PRT system (with the partial exception of WVU) have been shot down by politicians for non-technical reasons before they could go live - in some cases at the very last minute. But one will be built soon. Either the Cardiff one, or another one at Heathrow airport will be the first full implementation of the PRT concept to see active service outside a test track. That will be the real test - the test that lightrailnow dreads should ever happen. If it fulfills even half its promise, it will cause a revolution in transit. If it fulfills all its promise, private cars (for most journeys, for most people), as well as buses and trains will be obsolete within a few years (maybe superfast long distance trains will still have a role, but I wouldn't bet my horse on it).

Pardon me for resuscitating such an old thread, but...

I did want to make a couple of observations on PRT. And by PRT, I am refering to individual vehicles with a dispersed destination pattern, NOT peoplemovers like in airports or horizontal elevators.

I think there are thre major problems with PRT systems. First, there is always going to be a security/safety issue. Too small a vehicle with only a few people in a car is goign to definitely be a source of violent crimes. It will also mean an awful lot of vandalism. I know you can use cameras and such - but that has not yet proved to be effective in any other case, I don't see it being a true deterrent here, either.

Secondly, it's too complicated. To really be an effective replacement for the automobile you would need to service a wide number of scattered stations. This gets really complicated really fast. You need to fund a huge number of vehicles, and also a large number of stations which may get very little use. All those vehicles and number of tracks and stations means a lot of maintenance. And when something goes wrong with the system as a whole, you are stuck.

Lastly, it also misses out on the whole economy of mass transit to begin with - economy of scale. Mass Transit works because it is a standard set of compromises - fewer destination points and traveling together. Where is the major gain in efficiency, besides vehicle standardization (which would actually work against acceptance)?

Lastly,

What happens when two lines intersect? That means having double the height of the guideway.........much more pricy.
What is there are 4 people on the cab and they all want to get off at different stations?.............slow, especially when loading/off-loading.
Not wheelchair accessible.
They can go down the middle of the road but what about intersections where cars/truck have too cross it at every street? Again it would need a very high height guideway, more money. It would therefore have to be 4 stories above ground where two cab lines converge at an intersection. I wouldn't want to climb 4 stories to say nothing of the elderly or young kids, baby carriage, with groceries, luggage, napsacks.
What about cars/trucks making left hand turns....again would have to be elevated to.
higher heights.
What about road maintenance and snow clearing costs? How would you snowplow around the stations?
How would they avoid overhead wires? Again more height, more cost.
How would people get to these little stions? Public transit which means public transit would be subsidizing private transit.
What is everyone on the next 10 cabs doesn't want to get off at your station...you end up waiting forever in a cab that may only have room for four or five people with 8 at the station. Thats means they may have to wait for a couple more cabs til one gets to their station for drop off but now there are 10 people waiting at the station and so on......
What if the pylons down the road to support the guideway conflict with sewer or underground electrical lines?
What about waiting in the rain? They can't stand on the station floor because people get off there........more money for shelters.
This to say nothing of the fact that not everyone would want one down their street blocking traffic, shrinking sidewalk length and parking.
Also it takes forever just to get business/home owners/planning depts to agree on regular transit use with committees.....can you imagine the amount of time it would take to get the regulatory plans to pass which assumes everyone around the line and stations agree to it which is between zero and nil.
The only way this could even make some sence if down a cab-only road much like a bus rapid transit totally street and intersection free and then if you build that you might as well just build a bus road with with stations.
This thing would have to be atleast two stories of the ground and the stations would have to be in the middle of the road to say nothing of having to board the cabs in the middle of the road. I wouldn't want to wait for a cab in the middle of the road.
Its a pie in the sky idea that simply looks good but the logistics are impossible to deal with.

I read that Heathrow airport is looking at investigating a PRT system to integrate the various hotels and staff and long term parking sites to the various terminals. This would enable them to replace the dozens of shuttles buses that connect all the various sites around the airport.

This is to reduce vehicle emmissions in the area so they can build a third runway.

It won't work. The stations they're proposing aren't wheelchair accessible, thus this required component will increase their bulkiness. The only way I see this working is as feeder lines to subway stations in suburbia. However, this is achieved easier, by building parking lots at stations.

If Heathrow does go ahead with the system it is designed to replace the large fleets of buses that shuttle between the large hotels and various large employee and long term car parks. Not including airport and office park car parks, Heathrow has about 38,000 car park spaces the majority of which are connected by shuttle buses. These won't be little shuttles but probably like existing airport shuttle trains. The exception being to a convential light rail network with trains linking all the sites in one big long line. One shuttle might going to Northside staff car park, or purple parking, the A4 airport hotels or any number of sites. These would free capacity on the congested airport roads and reduce passenger anxiety about reaching the terminals.

I found an interesting project. Now first off I'm not Korean and don't live there, so from what i read when flipping through the Korean forums and doing my own research that Seoul is supposed to get something like the rest of the P.R.Ts. I guess it's called SkyTaxi and it's going in one of Seoul's main business districts. Gangnam I think it was.... Anyways I found a picture and a real "SkyTaxi" built buy one of Posco's subsibaries on a test track somewhere in Korea. The one built buy Posco was a different prototype trying to make it's way into the market. The SkyTaxi though is a different project.... I guess there really happening....

I guess since Seoul has probably one of the world's if not the world's worst traffic problems, that this will suit them perfectly...

..Also from what I have read, Gangnam is also building a monorail and also this P.R.T stuff.. There's going to be no use for cars, my goodness... But they are both separate projects.. The posco (Postech) prototype does not have any plans yet to where they might build... Maybe Daegu or something..


SkyTaxi ( SkyCab )

http://imgnews.naver.com/image/023/2005/01/13/200501130412_00.jpg

http://faculty.washington.edu/~jbs/itrans/skycar4.gif

http://faculty.washington.edu/~jbs/itrans/skycar15.gif

http://faculty.washington.edu/~jbs/itrans/skycar1.gif



..The last three pics are just old rough sketches. There are newer ones and diagrams and such, but I just couldn't find the website...

Skycar is a Korean entry into the Personal Rapid Transit technology race. It is being developed by a Korean company called Woo Bo Enterprise Co., Ltd, located in Seoul, Korea. This infopage is based on a brochure recently produced by Woo Bo that is written in Korean. Little is currently known about the state of development of Skycar, but it is known that the company is actively seeking funds for engineering and testing. Work on Skycar began in 1992 and several feasibility studies for specific sites in Korea have been conducted. It appears that the Skycar PRT concept is very similar to the American TAXI 2000 PRT concept with some important differences in the design of the guideway and in the use of an electromagnetic switch instead of a mechanical switch. Other differences will be revealed after patents have been obtained.
According to the Woo Bo brochure, the system would feature 3-passenger vehicles, a linear motor, and guidewheels for stabilization and steering. The guideway is a "U" shaped steel structure with integrated power supply, signal, communication, steering and control equipment. Performance is stated to be a minimum headway of 1/2 second, maximum capacity of 7,200 vehicles per hour, average capacity of 6,000 vph, maximum passenger capacity of 18,000 persons per hour and average capacity of 9,000 persons per hour (at an average occupancy of 1.5 persons per vehicle). Average speeds are expected to range from 45-60 kph. A propulsion system development study and a control/communication system development study were performed by an outside company in 1994. Woo Bo formed an adjunct Transportation and Urban Research Institute in 1992 to assist the further development of the Skycar concept.

..Another company in Korea is working on the same prototype or something like that... Not really sure...

The Posco Prototype

http://www.postech.ac.kr/~wing/images/driving%20PRT%202.gif

PRT Test operating in a 40m test track, PIRL, POSTECH, Pohang

nah, I don't want that PRT in Seattle, it would create a mass grid of guideways and all that, I think it's better for small and low destiny towns. I would rather stick with monorail, light rail or subway, or even buses. They look like toy cars on flimsy guideways.

I also have to say, I wouldn't trust them in a earthquake. SkyTrains are large and the pillons massive and are built to withstand huge eartquakes, I can't see how these would.