Track Network
Imagine a network of elevated tracks along which vehicles are magnetically levitated, and guided under computer control. Apart from entry and exit points there would be only merging and dividing intersections, and fly-overs. This would allow vehicles to traverse the network without slowing or stopping, making average speed close to cruising speed. The technology to do this exists now.

Capacity
Let's look at some figures... If we take vehicles of length 10 ft moving at 40 mph with very little gap between them, we get a capacity of (5280/10 vehicles per mile) X (40mph) = 21120 vehicles per hour, equivalent to about 9 overcrowded 70mph motorway lanes. At 80mph the capacity of a single track is 42240 vehicles per hour, equal to 18 motorway lanes.

Track Loading
For vehicles weighing 1 ton, the maximum track loading is 1 ton per 10 ft - much the same as pedestrian bridges; so construction costs will be low, about 1/10 that of motorway. In many areas the potential traffic flow is a small fraction of the standard track capacity. Vehicle spacing on these routes could be set so that track loading is less than the standard, allowing lighter and cheaper tracks. In remote areas a form of synchronized, bunched, single track working with passing loops could be implemented. Even this could still have a capacity similar to a current motorway.

Suspension & Energy Use
The passive magnetic levitation suspension used while on track, eliminates track wear and noise and, with suspension drag (the equivalent of rolling resistance) a fraction of that of conventional tyres. This, together with the elimination of speed changes and a control bias towards train-forming to reduce air drag, will reduce energy usage by at least two-thirds.

Control & Safety
What about the computer control? Is it safe? On-track safety can be designed in. Human errors, the main cause of accidents, will be eliminated. With total computer control of all on-track vehicles, response to any incidents will be almost instantaneous, allowing all vehicles likely to be affected, to perform controlled stops without shunts. A 'tactical level' of control would manage vehicle spacing while vehicle systems would also monitor spacing and closing speeds, signaling directly to other vehicles. Adaptive routing will automatically direct other traffic away from the affected area. Merging involves having the joining vehicles position alongside gaps formed in the traffic stream and then move sideways into them. This is similar to joining a motorway from a slip road. Following a merge, gaps would reduce where possible to minimize drag. Track capacity, especially at higher speeds, is so great that generating gaps for joining vehicles, should be less of a problem than the forming of trains to reduce air drag.

Performance
Using an out of city speed of 80mph these vehicles will out perform all other transport systems up to 200 miles. Once a 150mph trunk route network is in place, they will be the fastest transport option up to a distance of 400 miles, only air travel being quicker above that. Commuting 100 miles within an hour will be possible.

What type of vehicle will this involve?