This the second of two guest posts is from commenter Icebird looking at PRT, see the first one here

A short history of PRT

For an idea with such obvious (to me anyway!) potential, PRT has had an enormously difficult time going from the drawing board to reality.

The first major flurry of activity on the concept occurred in the 1970’s, with companies like the Aerospace Corporation and Cabintaxi working on the concept. Governments changed, funding was directed elsewhere, and development stopped. The one survivor from this era of work was the PRT system in Morgantown, West Virginia. The system doesn’t really match the model of a “modern” PRT system – it uses large vehicles, carrying up to a dozen people instead of small vehicles. That had a flow-off effect on the size of the infrastructure.

The system still operates reliably in both scheduled and “on demand” configurations, and it works well for the particular transit challenges that Morgantown faced, but the high cost deterred others from copying their model.

In the 1990s and 2000s, Dr Ed Anderson of the University of Minnesota devoted decades of his life to working on the concept, and a PRT system was almost built in Rosedale, Illinois (near O’Hare Airport). Unfortunately Raytheon, the engineering company tasked with turning the system into reality underestimated the crucial importance of keeping costs as low as possible. They built a test system over-engineered to within an inch of its life. The cost ballooned, the city got cold feet, and a major opportunity was lost. The company that Dr Anderson founded to develop his PRT system is now largely dormant.

This period was marked by feasibility studies in various cities: Tacoma, Washington; Cincinnati, Ohio; New Jersey. If the consultants had a significant interest in building urban rail systems, they tended to conclude that PRT wouldn’t work, while the more open minded studies usually concluded that the technology had potential, but please would someone else go first?

Advanced Transport Systems aka Ultra in the UK has had the most success in getting its system into the real world. It received government funding to build a test track in Cardiff, and for a while it looked like Cardiff would be the first city in the world to have a modern PRT system. The project was delayed to allow for competitive tendering, the government changed, funding vanished again.

In the mean time BAA invested in Ultra, and decided to build a PRT system to link Heathrow’s new Terminal 5 with a distant carpark. Construction was completed in 2009, but an extensive testing programme delayed the official opening of the system until last year.

In the meantime Dutch company 2getthere started their PRT system at the Masdar “eco-city” in Abu Dhabi. The Masdar approach was to build the entire city on top of a basement level where the PRT vehicles would operate. This model doesn’t really lend itself to duplication, and the scope of the PRT network has been steadily scaled back as Abu Dhabi’s ambitions for the Masdar project diminish.

The first application of PRT in an existing urban setting will occur in Amritsar, India, where a 3.3km 7-station system with 200 vehicles will link the city’s train and bus stations with the Golden Temple, a major destination for tourists and pilgrims. This system is due for completion in 2014.

Hands-on with the Heathrow pod system

I visited the UK in January, and like any good transit nerd I took a half hour detour to try out the PRT system at Heathrow airport.

The PRT system is located at the shiny new Terminal 5. It took a little bit of hunting around to find the system. It’s located on level 2 of the parking building adjoining the terminal. If you follow the signs to “Business Parking”, you’ll end up in the right place. (Please excuse the iPhone photography).

The station at the Terminal has three vehicle bays, all of them stocked with empty vehicles when I arrived. The bays are arranged in a diagonal configuration (think angled parking spaces), and the vehicles back out, so you can leave from any bay without being blocked in by vehicles stopped ahead of you.

A helpful speaker invites you to touch the screen to begin – all of the bays had their own touch screen terminals. You select your destination (either Car Park A, or Car Park B), confirm the destination, then the station and pod doors open.

The pod has two bench seats facing each other. The pod could accommodate 4 people sitting, plus lots of luggage. You could fit a wheelchair or bike in the pod as well. There are button panels on either side of each bench seat. To your left: Close, Open and Start. To your right: Information and Alarm. You press the Close button to shut the doors, then Start to get the vehicle underway. There are three video screens in the pod to show information on your progress, or potentially anything else the operators could think of.

The Ultra system uses rubber tires on either concrete or flat steel, so the journey isn’t as smooth as a pure steel-on-steel rail system. The Heathrow system has fences running on either side of the guideway, which presumably improves safety at the expense of aesthetics. I suspect they aren’t completely necessary, but Ultra have erred on the side of safety until the system’s track record has been proven.

The station at Car Park A was at ground level with 2 vehicle bays. I stepped out, snapped some pictures, then returned to the terminal. Entering and exiting the Terminal 5 station you catch glimpses of empty pods waiting out of site, ready to shift into vacant bays.

Applications in New Zealand

One of the fun parts about transport blogging is planning the transit systems you wish would be built. So where would I start?

I actually thing the best place to start wouldn’t be in Auckland at all, but in Wellington. The Regional Council is in the middle of a long-running planning process to determine options for the “spine” linking Ngauranga Gorge with the airport, via the inner city and hospital.

Your initial system might be a loop that starts at Westpac Stadium, passed the railway station, heads down Lambton Quay, Manners mall and Courtenay place, then loops back along one of the waterfront roads (passing by Te Papa and ASB Stadium). You could then add up a loop to head up Kent Terrace, past the Basin Reserve to the hospital. To connect with Kilbirnie and the airport, you’ve got two options : use the existing Pirie Street bus tunnel, or the Constable Road pass (you could probably use both). The system would probably work out cheaper than Ceila Wade-Brown’s light rail system, and reduce the need for a very expensive expansion of the Mt Victoria tunnel.

In Christchurch, PRT could take the place of the proposed City-to-University light rail system, a pet project of Bob Parker’s that seems to be an idea in search of a purpose.

For Auckland, I’d begin with a basic loop that went up Queen St to K Road, then returned to the waterfront via Symonds Street. Think of it as a basic “proof of concept” system that would link the downtown’s major shopping areas and the university. You could add a second “downhill” leg along Hobson Street to serve Sky City and the hotels and apartment blocks along that road.

Once the initial system is proven, you could expand it to area served by the Inner Link bus: Ponsonby, Parnell, Newmarket.

Stage three? Let’s get really ambitious, and tack guideways on to the Auckland Harbour Bridge, connecting our inner city loop with the north shore. Hey, we just added three highway lanes of capacity to the harbour bridge in each direction, and we spent maybe $50 million on the harbour crossing instead of $5 billion.

In looking at the question of “where do send the PRT network after it crosses the bridge?”, I’m going to avoid the busway completely (we’ll leave that for future rail systems), and instead I’m going to head west, putting in a loop that heads through Northcote Point and Birkenhead, and returns via Onewa Road. The loop could connect with the busway at Akoranga (giving residents of Northcote and Birkenhead an easy way to head north to Albany), and perhaps continue on to Takapuna.


Being a fan of PRT requires a lot of patience. For a system that can be built quite quickly, seeing it get to a position where it can start realising some of its potential seems to have taken longer than you would believe. But I’m getting increasingly confident that the proverbial “tipping point” is near.

For years, critics of PRT were able to say “well, there isn’t a PRT system operating anywhere in the world”. Now there is, and both Heathrow and Masdar seem to work pretty well. In two or three years, we’ll be able to evaluate the Amritsar system. If it proves successful, I suspect there will be a stampede of cities looking to build systems – when it comes to innovation in public transport, everyone wants to be the second city in the world to implement an idea.

In a comment discussion on this blog last year, Nick R doubted that a PRT system would be built in Auckland in our lifetimes. I’m not quite so pessimistic. I think by the time that the City Rail Link is completed, there will be multiple PRT systems in operation around the world providing real world data to assess its suitability for Auckland.

If PRT can prove itself in high-capacity operation, I see it as a real game-changer. It’s flexible enough to apply to even difficult transit situations, it could act as a feeder for the rail system, it could reduce the need for allocating so much space to parking in the suburban commercial areas, it facilitates those suburb-to-suburb journeys that bypass the CBD completely. The recent discussion document about paying for Auckland’s transport wishlist illustrates the astronomical costs of current solutions to Auckland’s transport issues. Maybe its time to look at more left-field alternaitves?

Until such time as the concept is proven to be completely unworkable, I’m going to remain a cheerleader and advocate for PRT

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  1. The only place that this will be used in New Zealand is Crazytown.

    There is NO WAY that PRT will get a look-in in Wgtn or Chch, when you consider that (a) you will be putting it on an elevated pathway (a concrete monstrosity on Lambton Quay or Courtenay Place? No thank you!); and (b) these cities are both vunerable to earthquakes.

    When you mix those two reasons together, you have so much risk built into an expensive system that there there be no politician or private investor will to touch this with a barge pole of any length.

    Me? I’m waiting until they start handing out personal solar & wind-powered perpetual motion rocket-packs. That’s where real freedom of transport lies (downside being the weather of course).

  2. Hi Seamonkey good to see your interested in this blog as well as Wellington architectural forums.

    I totally agree with you. The aesthetics of an elevated system in Wellington either along the Quays or the Golden Mile, would never wash. Any local politician who tried to get PRT in Wellington on an elevated system would be a fool.

    Even if the transport benefits of PRT in Wellington were proven, the social, visual and urban fabric impacts of the infrastructure need to be considered.

    Personally I don’t think a PRT system would be the right solution for an urban spine proposal like Wellington. Wellington needs a high capacity system (someone remind me how many passengers use the bus at peak time on the golden mile 20,000?) and the buses are currently congested so it needs to reduce the number of vehicles. Wouldn’t PRT be to low capacity and increase congestion rather than reduce it. Wellingtons Golden mile solution is probably better buses or light rail.

    PRT might work elsewhere though????

    1. “The aesthetics of an elevated system in Wellington either along the Quays or the Golden Mile, would never wash.”

      Compare with the monorail system in Sydney with its ugly elevated track cluttering up streets. Yuk!

  3. no, there isn’t a PRT system as you define it operating, your examples are simply shuttles between fixed points

    1. No, there isn’t a PRT system as *you* definite it operating. The Heathrow system offers on-demand operation (rather than scheduled operation), and it allows you to travel non-stop to your chosen destination, which can be be any station on the network. I’d consider those the critical features of PRT.

  4. You’d never get a harbour bridge PRT crossing for $50 million. Getting a cycleway on the bridge is going to cost $32 million. Sorry but I think your cost estimate are fanciful, they are out by at least an order of magnitude.

    1. Sure it was a pretty rough and ready number, and the cost would rise depending on how much of the infrastructure either side of the bridge you decide is part of the cost. Building the physical guideway might be a bit more expensive than the cycleway (over the equivalent stretch of bridge), but I’m not sure it would “orders of magnitude” greater. Dimension wise, they would probably end up being pretty similar. A PRT guideway would have to carry more weight, but it won’t have to support train-carriage type loads.

      There’s no point in crossing the bridge until PRT can prove itself as a high-capacity carrier (which I know most of you are convinced will never happen), but if it does – well a guideway in each direction would give you the exact same capacity at the proposed second Harbour crossing. You could multiply my figure by a factor of 10 and it would still represent a saving of billions over the cost of another multi-lane bridge or tunnel.

  5. Agree with Seamonkey & PBY on the aesthetics (or lack of) for elevated guideways in Wellington. Be bit like the Sydney monorail, but worse (two way guideway). Not proven in the trunk rapid transit roll, shouldn’t even be seriously considered for Wellington spine. Surface options more likely (ie LRT, BRT). If there was ever a need for a completely grade separated route, then either go underground or via the motorway corridor.

  6. according to the graph in this post, buses are already carrying more than a third of the people across the AHB in the morning peak and they’re providing it from an existing, ubiquitous network

    if that’s around 18,000 person trips, you’d need a full 6-seater PRT vehicle every 3.6 seconds to equate to that

    what is the vehicle’s unit cost? because you’d need eight or nine to provide the seated capacity of a bus

    I’m not meaning to sound negative, just realistic

  7. “In Christchurch, PRT could take the place of the proposed City-to-University light rail system, a pet project of Bob Parker’s that seems to be an idea in search of a purpose.”

    1) It does have a purpose. The proposed route (CBD-Riccarton-University) is the busiest, most highly developed, and fastest growing corridor in the city. Riccarton is like a second CBD, and it continues to develop and grow in importance. Light rail is planned to enhance this, and encourage urban renewal along the length of the corridor 2) Yeah, good luck with that

    1. I would go further and suggest that linking the University back to the city centre is an absolute prerequisite to having a functioning city in CHCH at all. Without it nothing will have done to mend the ‘doughnut’ city syndrome that was evident before the quakes. And by linking I mean with a non car transit system that is frequent, fast, and modern. Appealing.

      1. My objection to the light rail system is not a knee-jerk reaction against rapid transit, but the cost of the system versus its potential benefits. It’s residential catchment area doesn’t seem large enough to justify it based on commuters. Are university students really going to be using it to head into town – when they could get off the train at Riccarton, and get most of the same shopping? Hey, maybe its a service to allow city centre office workers to quickly duck out to the mall on their lunch hours. I suspect Westfield would love the idea of the light rail system to their door.

        If you want a thriving city centre, you need to have people either working in the city, living in the city, or both. I just don’t think the light rail would generate much return on investment when it comes to urban renewal.

        1. One of the main points of the light rail proposal is to facilitate more people living and working in the CBD. Furthermore, the corridor it runs along is one of the most densly populated (residential and commercial) in the city, so I don’t know why you think its catchment is limited. Added to that, connecting with transport hubs in the CBD, Riccarton, and University will increase the catchment further. Riccarton Rd is also saturated with traffic from morning to evening. Purpose and benefits for Africa right there.

  8. The ‘idea in search of a purpose’ you’ve suggested for CHC LRT. Isn’t this a description of the PRT?

    Believe me, I’m not anti PRT as such. I catch an elevator at work several times a day. On call, micro public transport. Only works in the vertical dimension but would ride a horizontal one if it was available.

    However, lifts work on very small runs at considerable expense and are required because there is no other practical way to service very tall buildings.

    PRT is basically automated and intelligent paratransit. Jitneys (styled by sweet young Uni design students) that run without a driver. It might be better to import vast numbers of drivers from developing countries and pay them a pittance.

    You will need to find the following to make PRT work:

    a) reduction in vehicle cost to below what a user might pay for a motor vehicle, while retaining comfort
    b) unobtrusive infrastructure. Sad to say, while a motorway overpass is seen as obtrusive, a normal suburban street isn’t. People expect to see it. But monorail beams, tram wiring, guideways, rails, people notice these things and complain about them. For them, the macadamised road is normal, the guideway an intrusion.
    c)out-do railway signalling. We have the best of the brightest earning big dollars trying new systems doing sat nav, interval signalling, intelligent train spacing and so on, and still no-one is perfectly happy with reducing train and tram headways below one minute.
    d) and somehow do all this in a way that fits a niche between mass transit and paratransit and private motoring.

    If you tell me this system will replace the Yamanote line I will not believe you. If you think they will give up a lane of the Harbour Bridge, you’re wrong.

  9. Ultra Fairwood has put together a 3D visualisation of the Amritsar project. I don’t expect it will change anyone’s mind, but I think it’s still interesting to look at:

    Perhaps someone needs to do something similar for the City Rail Link? 🙂

  10. I know I might be a bit late to this particular thread, but this system would be perfect to quickly shift passengers from Auckland Airport to Puhinui Station and vice versa. Turn up, get in your pod and go. User pays. No wait for a bus, get a pod all to yourself, no sitting in traffic, no stops in between, just ride the unobstructed, electric, express, elevated track until you arrive at your destination. Would be a 10 minute ride at most. The pods could be automated, starting slow at each end, and speeding up through the middle section. If there are a lack of pods at one end, then empty pods get sent back the other way on the loop to balance it out.

    Everyone else in this thread (5 years ago) was assuming that rail to the airport was a definite, so their suggestions are about CBD stuff. Nowadays we need to look at alternatives for airport connections, and I think this would definitely be something that could work.

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