Elevator Speech for PRT

This is really a little too long for an elevator speech, but I don't think you can capture the power of Personal Rapid Transit in 30 seconds, but here's a try.

PRT is elevated, uses computer controlled small vehicles, with offline stations. Vehicles wait in the station for passengers (in most transit, people wait for vehicles), and go line speed, non-stop, the whole trip.  The vehicle is small enough that there's no need for schedules--a single rider is enough to move it, so there's no waiting, anywhere, unless demand is so high that lines develop in the station. Because everything is light and small and top speeds are moderate, structural loads are moderate, which means the guideway can be light and small--and cheap. Not as cheap as a ski lift, but not too far behind, and a lot more useful.

Our design uses an on-board switch, which means we can run the vehicles arbitrarily close together (where a train has to move big pieces of rail to change routes--no closer than about 30 second headway and most require 3-4 minutes). Simulations on complex systems suggests that capacity with 1/2 second headway tops out at about 5000 Vehicles Per Hour Per Direction--about 5/7ths of perfect. With a 3 passenger vehicle, this means 15000 PPHPD. Central LINK peaks at 4000 PPHPD with 6 minute headways at rush hour, and the busiest subways in the world can only manage 25K with 2000 passenger trains, cost 10 or 20 times as much and take a lot more space.

Our company hasn't sold a real one yet, but we have a full size working prototype, a 1/8th scale test track, and by far the most sophisticated simulator that I'm aware of anywhere in the transit world.   Three of our competitors have systems running, all much lower capacity than our design: Morgantown, WV; Heathrow Terminal 5, London; Masdar, Abu Dhabi. (Masdar is almost comically incompetent--we helped with initial planning, but then they went with a lowball bidder, who really couldn't pull it off. Morgantown's been working almost flawlessly for 30 years, Heathrow for 3.)

None of these systems demonstrates the real power of PRT, which is that the system is arbitrarily expandable and benefits from network effect.   We are unaware of any theoretical limits to the capacity or scope of the Skyweb Express design, although there are lots of ways that bottlenecks can be created...system design and simulation is important.    I have done several simulated layouts with over 250 km of guideway, 175 stations and 5000 vehicles...it's pushing the capacity of a 3GHz processor, but our design is highly distributed--only optimizations are centralized; all actual control is localized.  I believe that in the long term, PRT will completely replace municipal buses, trolleys and subways--basically anywhere population density exceeds about 5 rides per day per acre.

Seattle activist group: www.gettherefast.org 
Our company: www.skywebexpress.com