ULTra (Urban Light Transit) is a personal rapid transit system developed by ULTra PRT,[1][2] (formerly known as Advanced Transport Systems). The first public system using ULTra has been constructed at London's Heathrow Airport, and has now opened to the public.
To reduce fabrication costs, the ULTra uses largely off-the-shelf technologies, such as rubber tyres running on an open guideway. This approach has resulted in a system that ULTra believes to be more economical; the company reports that the total cost of the system (vehicles, infrastructure and control systems) is between £3 million and £5 million per kilometre of guideway.[3]
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The system was originally designed by Martin Lowson and his design team, Lowson having put £10 million into the project. He formed Advanced Transport Systems (ATS) in Cardiff to develop the system, and their site later served as the location for buildings its test track. ULTra has twice been awarded funding from the UK National Endowment for Science, Technology and the Arts (NESTA).[4] Much of the original research on ULTra was done by the Aerospace Engineering department at the University of Bristol during the 1990s. Recently the company renamed itself to "ULTra PRT Limited" to better reflect its primary business, and moved its corporate headquarters to Bristol.
The personal rapid transit, or PRT, originally developed in the 1950s as a response to the need to move commuters in areas where the densities were too low to pay for the construction of a conventional metro system. Using automated guidance allowed headways to be shortened, often to a few seconds, but in some cases fractions of a second. This increases the route capacity, allowing the vehicles to become much smaller while still carrying the same passenger load in a given time. Smaller vehicles in turn would require simpler "tracks", smaller stations, and lowered capital costs as a result. Smaller towns and cities that could never hope to fund a conventional mass transit system could afford a PRT, and the concept generated intense interest.
Numerous PRT systems were designed in the late 1960s and early 1970s, many as a result of the publication of the highly influential HUD reports. In general, these systems intended to use small four to six passenger vehicles, but most evolved to larger designs over time (see Alden staRRcar). As they did so, vehicles and tracks grew heavier, capital costs rose, and interest dropped. In the end, only one production PRT system was ever installed, the Morgantown PRT, a government-funded demonstration system to prove the concept. Originally derided as a white elephant, the Morgantown system has since proven itself both reliable and relatively low-cost.[5]
In the time since the Morgantown system was installed, general technological improvements have led to a number of ways to lower the cost of implementing a PRT system. One of the simplest, but most profound, was the development of more efficient, reliable and quick-charging battery systems. Older PRT systems used electricity fed from track-side conductors in a fashion similar to a conventional metro, but these can be eliminated in favour of batteries that quickly charge up at stations or small charging strips along the route. Another change is the moving of the guidance logic from centralised computers to on-board systems of dramatically improved performance, allowing the vehicles to steer and switch themselves between routes on their own. This eliminates the need for a track-mounted guiderail able to steer the vehicle (see, for instance, the Ford ACT). Together, these changes mean the vehicle no longer needs strong mechanical contact with the guideway, which can be dramatically reduced in complexity.
In the case of ULTra, the guideway can consist of as little as two parallel rows of concrete barriers, similar to the bumpers found in a parking lot. The vehicle uses these for fine guidance only; it is able to steer itself around curves by following the barriers passively. No "switching" is required on the track either, as the vehicles can make their own turns between routes based on an internal map. Since the vehicles are battery powered, there's no need for electrification along the track. Instead the vehicles recharge when parked at the stations. As a result, the trackway is similar in complexity to a conventional road surface - a light-duty one as the vehicles will not vary in weight to the extent of a tractor-trailer. Even the stations are greatly simplified; in the case of ground-level tracks, the lack of any substantial infrastructure means the vehicles can stop at any kerb. Stations at Heathrow resemble a parking lot with diagonal slots, with a rain shield similar to the awnings at a gas station.
For all of these reasons, the capital costs of the ULTra system are dramatically reduced compared to older systems. A 1980s Canadian estimate places the price of a conventional underground metro system at $75 to $80 million per kilometre,[6] about CA$190 million in 2008 dollars.[7] The Morgantown PRT came in well over-budget and has a demonstrated cost of just over US$9 million per km in 1979, equivalent to about US$28 million in 2008.[8] Expansion plans from just after 2000 puts the costs of additional track at US$30 to US$40 million per mile.[9] However, the company estimates that an ULTra system can be installed, including vehicles and stations, for £3 to £5 million per km of track,[3] about US$5 to US$8 million, as of 2009[update]. This cost includes extensive sections using elevated guideways, which are much more expensive than at-grade versions.
The electric-powered vehicles have four seats, can carry 500-kilogram payload, and are designed to travel at 40 kilometres per hour (25 mph) at gradients of up to 20-percent, although the company has suggested limiting operating routes to 10-percent gradients to improve passenger comfort. The vehicles can accommodate wheelchairs, shopping trolleys and other luggage in addition to the passengers.
Each pod is powered by a battery pack providing an average two kilowatts of power and adding 8-percent to the gross weight of the vehicle. Other specifications include a 5-metre turning radius, an energy requirement of 0.55 mega-joules per passenger-kilometre, and running noise levels of 35 dBA at 21.6 kilometres per hour and measured at a distance of ten metres.
The company has also developed designs for a freight version of the vehicle. This has the same external appearance as the passenger version, but its entire internal space is adapted to host a cargo capsule. These can be valuable in airport environments, where the network can be used to haul small freight.
The one-kilometre ULTra test track was launched in January 2002. The $4 million funding for the test track came from various sources in the United Kingdom government. One electric vehicle was demonstrated running at speeds up to 25 miles per hour. Accurate stopping was demonstrated and the vehicle ascended and descended a steep gradient. A single, rudimentary ground level station was shown.
Most of the test track guideway is at ground level. It is stated that in a commercial application, 90-percent or more of the guideway might have to be elevated. This elevated guideway is about 1.5 metres wide. According to a study of a hypothetical city-based installation, consisting of 19.8 kilometres (12.3 mi) of guideway (89% elevated), the total cost of ULTra track and associated civil engineering works is estimated to be £2.9 million per kilometre ($8.7M/mi). Per-station costs were estimated to be £0.48-million ($0.89M). Vehicle costs were not considered in this study.[10]
Terminal 5 at London Heathrow Airport is served by a 3.9-kilometre (2.4 mi) ULTra PRT system that connects the terminal to its business passenger car park, just north of the airport. The line has been built on behalf of BAA, the airport's owner and operator.[11][12]
Construction of the guideway was completed in October 2008. The line is largely elevated, but includes a ground level section where the route passes under the approach to the airport's northern runway. Following various trials, including some using airport staff as test passengers, the line opened to public usage in May 2011. At that time it was described as a passenger trial[13][14][15]. As of September 2011 it is fully operational and bus service between the business parking lot and Terminal 5 has been discontinued[16]. The pods use 50% less energy than a bus. It is near 24h service it - runs 22 hours a day. Full (develop) cost was £30m to develop. [17]
The developers expect that users will wait an average of around twelve seconds with 95-percent of passengers waiting for less than one minute for their private pod which will travel up to 40 kilometres per hour (25 mph). If the pilot project is successful, BAA have indicated that they will extend the service throughout the airport and to nearby hotels using 400 pods.[12]
In March 2010, the government of Haryana said that they are looking into a proposal to deploy the ULTra PRT system for rapid commuter transport in the city of Gurgaon. The city is looking at over 10 to 12 individual routes covering a total distance of approximately 100 kilometres (62 mi).[18]
Concept of similar looking automatic cars, was used in the 1993 game Syndicate based in futuristic city. The main differences were that cars there can be stopped or run in the "forward mode", on almost every part of track, also changing direction was possible on road crossing with special signs.
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