Originally published ©2005 Get On Board! PRT
Transparently disinformative
"If those people want to pursue PRT with
their own money, that's okay with me."
—the Minnesota Anti-PRT Activist
(Seattle P-I, cached comment #356)
Taxi 2000 Document Reveals Safety Concerns Can Make PRT Systems "Unworkable".
...The following are excerpts that show that Taxi 2000 itself believes that PRT is a very risky investment.
"Federal and State safety regulation of automated transit systems can make PRT systems unworkable. Since there are no examples of our technology currently in operation, we cannot predict what sort of state or federal government safety regulation might apply. At this juncture, the Federal Transit Administration - which would exercise whatever regulation might apply at this level - has left the matter up to the states. Management believes the states will look foremost to the work of a committee of the American Society of Civil Engineers, which has developed a set of safety standards for "Automated People Movers" (APM's). We have been following that work and think at this point it will pose only one problem: eg., "brick wall stopping" requirements for the control system (borrowed from railroad signaling practice). The requirement is that if one vehicle stops instantaneously, the next vehicle must be able to stop before hitting the stopped one. That requirement would inhibit the sort of minimum vehicle headway used in our design, but it would not affect operation of the first, lower density systems. In the context of PRT, "headway" means the nose-to-nose time spacing between two sequential vehicles. Setting a minimum allowable headway determines the maximum carrying capacity of the guideway. We will work to have the headway requirement amended, since we believe it is inappropriate to PRT technology, but there is no guarantee we will be successful in that regard." Source
June 30: "By popular request, I post an excerpt from the Taxi 2000's Risk Factors Document that acknowledges the Personal Rapid Transit headway problem is a major safety concern that would prevent a nose-to-nose PRT system from operating under current safety regulations." Source
That's not quite what the Minnesota anti-PRT activist used to say!
Late May 2005: "There is certainty that PRT is impossible and it's in Taxi 2000's Risk Factors document filed with the State of MInnesota [sic]. It says the headway problem[...] can only be solved by asking the ASCE for a change on their guidlines [sic] for APM's. ... something that's highly unlikely because professional engineers are unlikely to relax a safety recommendation that would surely result in crashes, injuries and deaths." Source
June 23, 2005: "I really doubt that this "project "will get more than a glance from Bill Gates. Like the rumored PRT project in Dubai, this stuff is meant to impress the suckers - investors and politicians. A savvy investor would ask to see the Taxi 2000 "Risk Factors" document filed with the State of MInnesota [sic]. The Risk Factors document clearly states that the headway problem is a problem that no technology can fix." Source
June 13, 2005: "If you want to know the real deal on PRT, read the Risk Factors document that the Taxi 2000 Corporation filed with the State of Minnesota. It says one of the risk factors is the headway problem (which cannot be solved by any sort of advanced technology). It instead suggests that Taxi 2000 would ask to have the guidlines [sic] for headways changed to allow pods to stop on a dime and subject passengers to gut-wrenching g-forces." Source
"If all passengers are seated, simple experiments show that a 0.5g [a HALF g] deceleration will not throw a passenger out of the seat... requirements of PRT safety is that the vehicle be designed for all passengers seated."
Safe Design of Personal Rapid Transit Systems, Journal of Advanced Transportation, 28:1, 1994





