Trade-offs Required in the Design of an Optimum Transit System


J.Edward Anderson, CEO and President, TAXI 2000 Corporation


Non-exclusive Exclusive
Two-way One-way
At-grade Elevated Underground



People transfer Vehicle transfer, at a "Y"



Through wheels Direct linear
Internal Combusion Air Cable Electric - synchronous Electric- pulsed DC Electric- induction
Fixed frequency Variable frequency


Primary Electrical Power

On board At central station At wayside


Wheel Track

Monorail Duorail
Non-adjustable Adjustable
Joint at guideway joints? - Yes Joint at guideway joints? - No
Heating required? Yes Only at switches No



Passenger wait? Vehicles wait?
Serves all stops Serves some stops Non-stop service
Standing sometimes Standing never
Group, 2 or more Private, 1 person only
Rush hours only Limited hours All day, every day (24/7)



None Manual backup No human drivers



Carries several people Carries single person
Standees allowed All are seated  
100,60,20,40,12 passengers 8,6,4 passengers 3 passengers
Also operates on streets Dualmode (steets and guideway) Captive to guideway
Hanging (suspended) Side-mounted Bottom mounted (supported)
Long throw distance Short throw distance



No switching possible Track moves Part on vehicle moves
Rotation aid? Transverse Longitudinal
Stability: Neutral Stability: Bistable
While in use: requires support While in use: self-supporting



Air cushion Maglev Wheels-foam Wheels - steel Wheels - air filled



Reinforced concrete Steel Composites
Relative to vehicle - wider Relative to vehicle - narrower  
Relative to chassis -  wider Relative to chassis - narrower  
Connection to posts - simply supported Connection to posts - clamped  
Joints at posts Joints away from posts  
Open Covered  
Steel? Plate construction Steel truss construction  
Walkways required? Yes At some places No



On-board vehicles At central center Distributed
Synchronous Quasi-synchronous Trans-synchronous Point-synchronous Asynchronous
Headway law? Fixed time headway Fixed spacing Fixed factor of safety
Single path Redundant paths
Analog Digital
Sensing of vehicle ahead? Through track Line of sight Combination

Note: The number of design combinations listed above is 10,110,857,908,322,304