The Dualmode Car Bus is the Best Answer


Dave Petrie

The Car Bus (aka VMT and PMT ) should be the front-runner, amongst dualmode candidates, primarily because of its smooth evolution, transporting conventional types (including the EV/hybrids) of cars. Among all new classes of urban transit (in the modern distributed city) dualmode is the ONLY type of system that can transport the commuter to/from one's home to the workplace. The percentage of commuters who can walk to/from a conventional bus/train station/stop, or a PRT station, is less than 5%, in a typical American city.

The PMT type of VMT does not DEPEND on the EV. An 800 lb. microcar can be powered to 60 mph by either a 16 HP IC engine or electric motor. Frank's Car Bus hauls conventional IC cars.

PMT baselined the small EV. It is the systems engineers job to look at the larger developing picture: Tying the pollution issue to the congestion issue is common sense and timely. A small car also makes VMT a lot more efficient. For instance, the Nissan Hypermini (built in 1997) concept car--60 mph, 80 miles range, 8'x4' footprint- helps in many ways: 32 can be hauled on a double-deck version of the 90' long German O'Bahn bus or HSST-200 . A single lane of the freeway--or an arterial lane-- can accommodate TWO lanes of the Hypermini. The capacity of sections of parking lots can be tripled.

Station spacing can be every 5-10 miles with VMT because the commuter is not required to walk to the transit station. In the 214 mile PMT that we devised in 1994 for the Puget Sound region, 38 stations were planned, an average of 5.6 miles apart. Similarly, Frank's comprehensive solution to the Southern California area requires 66 stations for Car Bus (ten second unload/load cycle).

With regard to safety, we should assume that the EV/hybrid microcar will eventually become the most popular car in the industrialized world. When that happens, the average amount of kinetic energy involved in most collisions will be less than 20% of what it is today. With hi-tech crushables being used in composite-bodied PNGV's, for example; and most hi-speed commuting is being done aboard a transporter on a dedicated guideway/busway, safety will be far above the present situation.

Charging EV's in VMT is done mostly in one's home garage or apartment parking space. In my conversion concept of the O-Bahn bus, I also show a device that grasps hold-down fittings on the underside of each EV (while in transport mode) containing a transformer primary to top-off the EV battery enroute. In summary, the small EV and VMT are natural companions, each making the other more feasible.

Dave Petrie is a transit consultant working in Seattle, Washington. Please contact him if you wish more details regarding his work and those in other parts of the U.S. he is in contact with.


Last modified: April 15, 1998