Automated Rapid Transit - What Size Vehicle is Environmentally Sustainable?

Sustainability in transport, defined as provision of better transport service at lower cost and with less environmental stress versus existing transport modes, is essential for the success of a new transport system. Whilst enormous amounts of capital have been spent on the transportation systems of today towards decreasing energy usage, pollution, and congestion, we have yet to implement urban transportation that can accommodate demands of modern societies and be sustainable.

As rail transport moves towards driver-less control, the question arises as to whether traditional large capacity vehicles remain the best application for the new automation technologies that have been developed. In view of the established dominance of the motor vehicle, the relative decline in train use (primarily brought about by the superior service offered by the car) and the lack of a viable alternative to the car, the authors have examined a range of automated transit vehicles and conclude that a system utilising vehicles of about nine passengers is advantageous in terms of sustainability, compared with traditional modes of rail travel or with Personal Rapid Transit (PRT).