There will be no points as used on railways and tramways. Vehicles will be magnetically guided to the correct exit of dividing junctions.

Track sections will be joined to form a network with

The track will be constructed of prefabricated support posts and bridge-like spans. It may be an ideal application of the 'Glass Bridge' technology being developed in USA. This should produce very light and strong structures with working lives times several times those of concrete.

Parking and Depots
Using mechanical handling, the cars could be packed into automatic parks/depots at five or ten times the density achieved in current multi-storey car parks. Some development work by parking operators would be required, but the prospect of having automated parking of this density, and the profits this could generate, should drive its development. Current automated warehouse technology could be adapted for this high-density parking.

Access Points
The spacing between access points will vary from 0.5 mile in town to 30 miles in the country. Major office blocks, stores and shopping malls are likely to have their own freight and passenger access points as will rest areas on the longer routes.

Capacity
With the track capacity at 40mph of 21120 cars per hour, equivalent to 8.6 motorway lanes, no access point needs anything like the full flow of one track-lane. It would be as busy as tollbooths on an overloaded motorway. It is hard to think of any city, suburban or country access point needing more than a quarter this flow. One car every three seconds is probably the limit for entry bays Ð giving 1200 cars per hour per bay. Four or five bays will be adequate, provided there are no delays waiting for gaps in the traffic flow.

Exit points may be a greater problem because queuing on the track is not an option. Here, the vehicles have to de-merge and slow, and perhaps even stop when there is congestion on the road being entered. There will usually need to be a number of lanes, say four, per exit point with space to hold perhaps four vehicles on each. This buffering should generally give adequate service with a similar throughput to the entry point above. Some busy exits may be built with greater capacity. If an exit point is choked, vehicles heading for it will automatically be directed to an alternative or, to travel the shortest available circuit to return and try again.

Layout
Most access points will be clustered within urban areas. Within such clusters the speed will usually be 40mph. Link and arterial routes will mostly use 80mph as will the normal national network. The superimposed 150mph network will provide for long distance and intercity travel with link lanes to the normal routes at about 30 mile intervals. This gives the flexible routing necessary to cope with failures. Track access points will be positioned such that one can be reached within 0.5 to 2 miles in urban areas and within 25 miles elsewhere. Opposite direction tracks outside of city areas will usually run on opposite sides of the same right of way. Urban tracks may form a mesh of linked (hexagonal) cells of one way tracks. This would reduce the amount of track required and its intrusion. Suburban areas will probably use a mix of these layouts.

Track Curvature
This is a transport system for use by the general public, therefore lateral acceleration of 0.5g is probably the most that is acceptable. This gives 25.6 degrees of bank and a perceived 1.12g. Rolling in-to and out-of turns will take at least two seconds. This gives turn figures for various speeds of:

Acceleration Lanes
For user comfort acceleration and deceleration should not exceed 0.5g. Higher figures are acceptable at fun fairs but not for a public transport system accept in emergencies. Acceleration distances for various speed changes at 0.5g are:

Most urban access points will be in clusters within 40mph track areas making the acceleration lanes quite short. In many cases the transitions to and from higher speed will take place along the track without the need for special lanes. Deceleration figures are of course the same as for acceleration.

Track Positioning
Opposite direction tracks can be mounted one above the other, side by side, or widely separated, as the situation required. Track will be one-way except in very sparsely populated areas where alternate working may be justified. As they are far less objectionable than even minor road construction, tracks will be installed along current and disused railway lines, roads, canals, field boundaries, etc, in fact anywhere where a curvature suitable for the section speed can be placed. Tracks only use ground area for their supports so have negligible effect on land use below. In cities they may sometimes be supported on the faces of buildings. Access points will be sited for easy access and where local traffic is not disrupted. Large office buildings and shopping centres are likely to have in-built access points so that passenger and goods vehicles have direct access from the track-way.

Parking and Depots
For the relatively light and standard sized vehicles, parking blocks/depots could use mechanical handling as is done in automatic warehouses. This would give packing densities several times greater than multi-storey car parks now achieve. Users will also be able to leave their vehicles at access points to be parked automatically. When again required, a vehicle may be ordered to be at a specific point at a specific time.

Construction
Track should be much faster to build than conventional roadway, as it will largely be a matter of erecting pre-fabricated supports and track sections onto prepared bases. Track build accuracy should aim to be much better than existing road and railways. It should be possible to manufacture sections very accurately in a specially designed factory, and install them so that excellent ride quality is achieved. Following construction, a survey car should be sent along the track to make an accurate recording of track shape. This should be repeated at intervals to detect any changes of alignment.

Coverage
Ultimately, for maximum benefit, the whole of the country should be served by the system with no point more than about 30 miles from an access point. It is important to get internationally acceptable, interface, weight and size standards which can be adopted world-wide. Given the use of the Channel Tunnel, perhaps with trains of these vehicles interleaved with Chunnel trains, or rapidly loaded onto them, the whole of Europe and beyond will be within reach.

As this is a very cost/effective transport system it may be particularly attractive to developing countries, by-passing the hugely damaging and costly road building phase from which western countries are now emerging.