Readers of this blog will know I used to talk a bit about Personal Rapid Transit (PRT) but have switched to a belief that it is now likely that robocars might fulfill the PRT vision before actual PRT can. To understand that, it is necessary to explore just why PRT has never really come about, in spite of being promoted, and possible for almost 40 years. The Morgantown Personal Rapid Transit has run since 1975, though it uses large vehicles and only has 5 stations, so it doesn’t realize the PRT vision of personal cars that go point to point in a network of stations. The ULTra system, with personal cars (which run on tires in a simple track) is being built at Heathrow airport.

I wrote an article on the reasons I have rejected classical, track-based PRT and then opened discussion on it in the Google transport-innovators group. The thread was quite vigourous. I had expected PRT fans to not welcome the concept, and to believe that robocars are still very distant science fiction, for indeed that is a valid objection.

I had not expected such a love of the general concept of shared transit that I would see people arguing that even if robocars were arriving soon, it would still be better to fill our streets with custom elevated guideways for a PRT system. Indeed, some advanced that we should not be building roads at all, that people would give up entirely on vehicle ownership in a PRT or robocar world and that providing garage to garage (or door to door) service was not necessary in the U.S. market, or could easily be done by just running PRT tracks to every house.

I understand the frustration in the PRT world. The ideas make a lot of sense, but no city will buy them. I contend that’s because municipal transit planners are highly averse to innovation. They are happy to buy 100 year old technology for their cities. They think farecards and web sites that can tell you when a bus will get to your stop are space-age innovations. Nobody wants to be the planner who bet on an untested technology that failed. That’s a career-ending risk. They would rather bet on old technology, and in spite of how well it is understood, see it go 100%, 200% or more over budget.

I predict that, once the technology becomes more real, robocars will win because they will be built bottom-up on a simple, already existing platform (roads) without any requirements to build infrastructure or run it. They will be bought by individuals, in particular by early adopters. Early adopters have money to burn on the latest hot new toys. They will happily waste it and buy the cooler model 8 months later. Cities don’t buy this way, they can’t. Cities buy technology that’s already obsolete before they even put it out for bid, and it’s very obsolete a decade later when it goes into operation.

Worse, transit requires monopolies. Either the city runs the transit as a monopoly, or it grants a franchise to a private company to build and run it. (That’s far more rare, since most transit runs with heavy subsidies in the USA.) Monopolies mean corruption (as they get large, they end up having more influence on the city officials than the customers do) and they mean monopoly-style customer service.

While robocars are still over a decade away, I fear that even though PRT could be built today, it will take it a decade to get over the marketing humps it has not managed to overcome in 40 years. By that time, robocars should be much closer to reality, and we’ll reach a point where even a transportation planner will realize the robocars will arrive soon enough to affect transit planning in the present.

Rather than being viewed as the enemy, robocars should be viewed as a way to realize the PRT vision without those deal-blocking new infrastructure requirements. But the PRT community is not yet ready to agree.

Read Robocars and PRT