Personal rapid transit derailed in the 1970s. Some are ready to give it another try.
The year is 2033. A bleary-eyed woman heaves her suitcase from a shiny baggage carousel in Los Angeles International Airport. Rather than hailing a cab, she steps into a white, streamlined pod attached to an overhead rail. The woman swipes her credit card and uses a touchscreen to indicate her destination, a pod stop near her home in Beverly Hills. The door closes, and her pod accelerates to match the speed of traffic as it merges onto the main guideway at 114 mph. The woman finishes her salad and plays Sudoku on her smartphone as the pod glides along silently. She’ll be home soon.
This is the kind of transportation experience being promised by personal rapid transit (PRT) or automated transit network companies. Traffic on PRT networks is controlled by a central computer, so collisions, traffic and even the stress of possibly getting lost could all theoretically be eliminated. PRTs can be powered by clean energy, and some proposed systems use magnetic levitation to connect vehicles to a high-speed guideway, eliminating pollution, noise and the usual wear caused by moving parts. A PRT network that spanned a large metropolitan region could solve most problems of existing public and private transportation.
Everything about PRT smacks of the future, but the technology’s here today. Or at least it exists — although the networks haven’t been built. There are only a few small PRT networks in operation worldwide, and there are several more under way, but none of them embody the potential of what proponents of PRT say the technology can offer. The oldest PRT network began operation in 1975 in Morgantown, W.Va., but a bystander could easily mistake the system for something other than futuristic. The Morgantown PRT network is neither personal nor rapid — each car holds about 20 passengers, the system runs on a ground-mounted rail, and the top speed is 30 mph. To be fair, technology has come a long way in the past 40 years, and besides, many today still consider the Morgantown PRT network a great demonstration of the reliability, safety and improved service that PRT networks could offer.
There are two other PRT networks in operation — one designed by 2getthere in Masdar City, a planned city in the United Arab Emirates, which would be the first zero-carbon, zero-waste, car-free city in the world. The other was completed by ULTra for London’s Heathrow Airport in 2011. And while both systems have been lauded as excellent demonstrations of PRT’s viability, neither system realizes the technology’s full potential. These networks have only a few stations, cover only a few miles, and have only 13 and 21 cars, respectively. Likewise, a PRT system being built now in Suncheon, South Korea, is of similar size and not intended to displace local taxi or bus services, but rather serve as a way to transport guests to the city’s upcoming garden expo.
Existing PRT networks have very specialized functions, said William Millar, former president of the American Public Transportation Association. For the technology to progress beyond airports and pilot cities, he said, something must change. Factors like rising fuel prices, growing populations and increased public concern about global warming all are forcing transportation methods toward greater efficiency, Millar said. But while PRT offers a solution for these problems, PRT’s track record makes Millar doubt that it will become a prevalent technology in the future. “Personal rapid transit is an idea whose time heretofore has never come. It has been tried in many different forms, in many different ways, and it has not yet found much of a market other than specialized circumstances.”
Perhaps the biggest hurdle for PRT is a social one. “Often these are services that are elevated in the air in urban areas, and people don’t want that,” Millar said. “It won’t be the technology that holds this back. It will be the institutional design concerns that people have.” Communities often view such proposals as eyesores and raise concerns about noise and other problems. Even if the system is actually small and silent, as is the case in many of the new systems being developed, it won’t matter, he said — overhead transit systems like elevated trains have conditioned the public to oppose PRT, even if their reality is totally different than what the public thinks it is.
The case still must be made that PRT is superior to existing transportation options, Millar said. “What you’re willing to do on your vacation in Disney World,” he said, “is not necessarily what you’re willing to do when you’re back home in the work-a-day world.”
Others aren’t so pessimistic. Several companies are striving to replace the car, bus and train with citywide networks of fast-moving pods. SkyTran, based in Mountain View, Calif., at the NASA Ames Research Center, is one such firm. The company is starting locally, petitioning the Federal Transit Administration (FTA) for approval to build a PRT system in Mountain View. But SkyTran also is aiming its high-speed system at large cities worldwide. The firm recently contracted with Tel Aviv, Israel, to build a line that could eventually be expanded throughout the city if the pilot is deemed successful.
Chris Perkins, vice president of government affairs for SkyTran, said the benefits of PRT are compelling enough to sway public sentiment and revolutionize transportation. “It doesn’t have wheels [or] a diesel motor. It doesn’t belch fumes,” Perkins said. “It’s essentially an all-electric, linear motor system that uses magnetic levitation so there’s no wheel contact. There’s no wheel noise as the vehicle is traversing our guideways.” What SkyTran’s PRT offers, he said, is “point-to-point, nonstop, on-demand service, which is just like a car,” except better. “It’s the kind of car we all want,” Perkins said. “You get in the thing, you go where you want to go and then it just disappears. No possible parking tickets to pay, no insurance.”
PRT networks like the ones SkyTran is proposing could replace trains, buses and even personal vehicles, to an extent. A single guideway is equivalent to three lanes of traffic, Perkins said, yielding potentially 11,000 passengers per hour. The cost to the consumer is about half that of owning a car, he said, and would cost a city about $9 million per mile to build, which is much cheaper than the cost of most traditional transportation infrastructure. The low cost and small footprint of PRTs are two reasons the technology is starting to replace automated people movers in airports, as it did in London’s Heathrow, and why a city like Tel Aviv will try it.
Perkins agreed with Millar that concerns about how PRT will look and sound are the most common worries from prospective clients. But he said PRT systems won’t necessarily mar the nation’s cityscapes. In fact, these systems could help clean up urban visual blight by integrating power lines and light and traffic poles into the guideway structure. SkyTran’s design is modular, so it could be mass produced easily, he added. “It can be built in factories, then shipped to the job site and assembled like Tinkertoys.”
SkyTran’s PRT relies on magnetic levitation, but in 2009, the FTA released a report citing key challenges around the use of magnetic levitation in urban areas. Obtaining right of way, meeting safety standards and traveling at speeds lower than what’s normally used for magnetic levitation were all key concerns cited by the report. However, the federal government has spent more than $250 million researching magnetic levitation, including a four-year research grant completed by SkyTran in 2010, and they’ve come a long way in providing solutions to all of those challenges, Perkins said. But so far, SkyTran’s projects have been relegated to the space already staked out by PRT in the past. The company’s vision of fast-moving citywide networks that can replace lanes of freeway traffic and branch out to every neighborhood is still out of reach. The Colorado Department of Transportation is evaluating whether SkyTran should build a guideway between Denver International Airport and nearby ski resorts. That system, if built, could possibly someday extend into a larger system used for more general transport, Perkins said. But for now, governments don’t see PRT as a main mode of transportation that will replace cars or buses anytime soon.
Last year, San Jose, Calif., conducted studies examining the possible use of a PRT network for transporting people both within San Jose International Airport and connecting them with nearby train and light rail systems. The reports found that PRT has potential, beating out shuttle buses and automated people movers in terms of cost and service provided to the user, but the studies also recommended that San Jose tread carefully.
PRT shows promise, said Laura Stuchinsky, sustainability officer for the San Jose Department of Transportation, but many unproven components must be worked out before the city invests. PRT proponents often point to existing systems in Heathrow Airport or Morgantown as proof that the technology works, and to some degree, those statements are fair. The systems have proven safe and reliable, but those small systems don’t eliminate concerns that PRT may not scale well, nor do they provide any comfort regarding the lack of a regulatory framework that governments can comfortably work within.
“We think there’s great utility, but there’s not a system proven yet that can handle large crowds like what would be coming off a high-speed rail station or out of our airport during peak periods,” Stuchinsky said. “We’d love to see these systems built in the U.S.” But there isn’t yet sufficient proof that such a system would work well enough for San Jose to build a limited airport network, let alone a wider network to serve the entire city, she said.
“We also don’t think automated transit networks [will] replace existing transit. We think the best initial applications, and there may be other applications, are weaving together existing systems,” Stuchinsky said. San Jose’s 2040 General Plan includes the development of urban villages, mixed residential and urban areas that would let people walk or bike to work while enjoying many of the benefits of a large urban center. PRT could connect such villages to larger transit networks, or cross barriers like rivers or freeways. PRT could deliver travelers along the final leg of their journeys, Stuchinsky said, connecting major transit hubs with common destinations.
Much as NASA or the U.S. military hires independent agencies to test the viability of a rocket or missile, she said, governments nationwide could benefit from a federal program that demonstrated PRT as a low-risk venture for both the government and private companies planning to build these networks. Few cities want to be a guinea pig for large-scale PRT deployment though, especially if they’re picking up the tab.
Peter Muller, president of PRT Consulting, agreed that the federal government should help the technology get a foothold in the U.S. Public opinion polls measuring PRT users’ satisfaction, Muller said, have shown that the technology is safer and provides better service than all other forms of public transport. The public loves PRT when it’s available — people just haven’t been given a chance to embrace it. Part of the problem, Muller said, is that the U.S. government still hasn’t gotten over its hurtful breakup with PRT in the 1970s.
The Morgantown system is considered by many today to be safe and reliable, but the network didn’t start that way. While still under development, the project was altered from an initial plan of a true PRT system to a PRT-group transit hybrid. To complicate things further, the project was rushed to completion by Richard Nixon, who wanted to see it finished in time for his run for a second presidential term. On the day the system was unveiled, Tricia Nixon, the president’s daughter, rode the first vehicle until it promptly jammed in the middle of the track, stranding her. “It took them three years to get it to work,” Muller said. “They had to start all over. It overran the budget, it overran the schedule, it embarrassed Tricia Nixon. It was a disaster.”
Since then, PRT hasn’t gotten a fair shake from the feds or regional transit agencies, Muller said. “The way public transportation is funded is a huge part of the reason,” he said. “They don’t encourage innovation. They don’t encourage people to fail and then learn from their failures. If you try something new and it fails, heads have to roll. This doesn’t encourage people to try something new.”
Another problem is that the way the FTA evaluates transit systems tends to undervalue PRT, Muller said. “They do what are called corridor studies. Well, PRT is a network system. It’s designed to operate in a network. It can work in a corridor, but that’s not its biggest advantage.”
Concerns that PRT may not be scalable are legitimate, Muller said, but the degree of skepticism and fear surrounding the technology is unrealistic. “The federal government should step up and fund a demonstration program with PRT and either prove or disprove its scalability, so cities that want to do it can feel some comfort that this is a system that’s been proven to really work,” he said. Cities like San Jose or New Jersey, which also looked at the technology in 2007, concluded the same thing — PRT has been around for decades, but the research and development required to demonstrate the viability of a large network is beyond most city and state governments.
Transportation is about improving quality of life for as many people as possible, Muller said. “If the government doesn’t [help], people are going to have to carefully tiptoe into this technology, and it will take a long time for it to become ubiquitous and that’s just a shame. It can solve many of our problems.”