Bigpedia PRT vs Wikipedia PRT

There's something called Bigpedia that uses a lot of the material from the Wikipedia PRT page... but also includes facts that PRT fanatics have kept out of the Wikipedia page including links to skeptical sites like mine and Light Rail Now's "Cyberspace" article.

Go to the Bigpedia PRT page and scroll down to "Disadvantages":

Disadvantages

Most planners say that no economically successful PRT system has been demonstrated, and there have been too many failures for a prudent person to spend public funds. Transit planners normally evaluate a new transport method as part of an intermodal network. In these cases, a PRT line may compete against a rail or bus line. When operated in an intermodal transit network, PRT may not fully realize the travel time reductions advanced by proponents, because connections to other mass-transit modes are only possible when the other vehicle arrives; a disadvantage where infrequent transit can be the weakest link in an intermodal system. Timed connections between conventional mass-transit modes, though rare, can be more efficient than PRT intermodal use.

The claims made by proponents depend on certain reasonable but nonstandard design features (see above). Many planners argue that if conservative ridership, operating expense ratios and inter-vehicle lead distances (for bus and train systems) are used, PRT systems are less attractive than bus and train systems.

In transit planning with standard ratios, if PRT were built in an existing high density corridor, it would be less efficient than trains. Only if additional capacity were required in a low density corridor, would it be more efficient than a bus line or automobile, since the capital costs of streets are already sunk.

Because of network effects, PRT is not fully useful until it is widespread. In this view, a small PRT system will not attract demand because it does not go to many destinations. Many people say that only a large PRT can attract sufficient demand to be self-sustaining. How it could grow from a niche to a local or metropolitan network is unclear to these persons. Growth to a national network is thought especially unlikely.

Skeptics say that PRT just idles entire vehicles, which is true. The effects of vehicular recycling at rush hours are also disputed by some transit planners, because they are simulations. Some skeptics have said that since gross capacities have to be comparable (because the same number of people are being transported in the same time), no advantage can occur. However, comparing capacity (people per hour), and capacity utilization (money per person per hour) is a fallacy.

Some experienced advocates claim that the chief problem is that PRT threatens existing livelihoods associated with cars, busses, trains and related services. Since the market in rapid transit has a limited (government) budget in each city, and existing options are the best-funded, existing options and organizations tend to win political battles. As of 2001, this may be changing, because existing options have been unable to solve traffic problems.

The claimed very high vehicle utilizations (vehicles are usually carrying passengers at full speed, rather than parked), means that there might be less need for, and investment in private vehicles, and auxiliary private services such as repair and insurance. Although these are social advantages, they directly threaten the livelihoods of many persons.

PRT systems may be as unattractive as other public transit. People cannot customize them to their tastes, and therefore rarely have anything approaching the enthusiasm shown for a new car. At Morgantown, most students use, but casually despise the transportation system, and recount stories of its failures. Some jokingly claim the term "PRT" is said to stand for "Pretty Retarded Train."

Some call PRT a prime example of a federally funded "pork barrel" project, one of many located in West Virginia due to the influence of Senator Robert Byrd.

A PRT system is said to have lower costs and automated operations. These could lead to simpler organizations and smaller staff at governmental transportation offices. This directly reduces the responsibility and authority of government officials, which in most civil service systems, reduces their pay. It does not offer much incentive to administrators to adopt it.

Many authorities say that the cost of constructing and operating the system is unlikely to be as low as claimed. Some systems (such as Morgantown) have had much higher costs than planned (Morgantown has to use steam heat to keep its tracks free of snow). Any new technology has to climb a learning curve, and for every new system, promoters must make speculative claims when asserting low construction and operating costs. Historically, costs are underestimated on transit projects and demand overestimated. Further, methods of recovering unplanned cost overruns can cause political and public strife.

The neighbors of such a system could oppose unsightly towers holding an elevated rail system, as well as the guideway itself. New infrastructure is hard to build, particularly without the support of the community.