The last mile in Tysons Corner, part 3: PRT?

Last week, Steve introduced Tysons’ “last mile” challenge, and Matt Johnson explored a series of busways as a solution.

A bolder proposal, for Personal Rapid Transit (PRT), generated considerable controversy among the GGW contributors over email. There is a range of opinions on this technology among the contributors as among planners in general and the public. Therefore, Steve has put together a piece arguing for it, and Matt wrote a counterpoint which we’ll post next.

Instead of waiting until Tysons’ very long term fixed-guideway transit, Tysons could become a visionary community by building and implementing a state-of-the-art PRT system at the beginning.

At least one company has developed a proposed plan for how PRT might be deployed in Tysons. For those of you unfamiliar with the debate on PRT, there are very strong opinions on both sides about this technology, ranging from fairy tale to rapture. Personally, I believe the reality is somewhere in between.

The big advantages of PRT are that waiting times are very short and all travel is direct. There’s no need to stop for other passengers to get on and off, no transfers, and one-seat rides to all destinations. If PRT works as advertised, then one could travel from a Metro station to their destination a mile or so away in 3-4 minutes rather than the 12-15 it might take with a circulator. It would also function much better for moving around within Tysons, which is currently laborious by any mode.

For comparison, Fairfax estimates the circulators would cost $9 million to purchase and about $5.8 million per year to operate. That would be $67 million for ten years, $125 million for 20, without accounting for replacement buses.

Cost estimates for PRT range from $7-15 million per mile, with Tysons on the higher end due to its already developed land. Because of the reduced weight and footprint of PRT systems, they cost significantly less per mile than other rail systems such as streetcars or light rail. The green loop shown in the PRT proposal cited above is about 4 miles of guideway, so approximately $60 million. All three loops look to be about 14 miles of guideway, or a total of $210 million. A company representative I spoke with believes revenues from fares can cover operating costs.

A potential source of investment is from developers. West Company owns about 10% of all the land in Tysons, but it’s mostly out of walking distance from the Metro stops. If that property were made much more easily accessible, the property value would significantly increase. Perhaps they would be willing to help fund the costs. Hotels might pay for track sections and stations that directly serve their properties.

Of course, developers could fund any mode, not just PRT. However, I don’t believe land owners would invest much in circulator buses compared to some sort of permanent infrastructure.

Is it risky to get out in front with a new technology like this? Of course. But streetcars are essentially 19th-century technology; PRT is 21st century technology. The technology has advanced enough that an entire city in the UAE, Masdar, is being built with PRT as its primary form of transportation.

Heathrow Airport in London will have the first operational, albeit modest sized, system in the next few weeks. Making PRT work in Tysons would not only solve the last-mile problem, it would expand the value of the Silver Line to the entirety of Tysons, and the system itself would make Tysons a destination in its own right, attracting additional visitors and investors alike.