Sir – Although I share Dr Ian East’s enthusiasm for trams (Letters, March 19), I fear that Oxford is not large enough to provide sufficient traffic to justify a viable tramway system.

In theory, a city needs a population of over a quarter of a million to support the capital cost of building a tramway system.

The French APS sytem (alimentation par sol) to which Dr East refers, is a modern version of the surface contact system which was proposed for the Oxford tramways 100 years ago. It is extremely expensive to construct, and is only justified in historic city centres, as in Bordeaux, for example, where overhead wires would be detrimental to the street scene.

The trams in Nice carry batteries to allow them to traverse the city centre without needing overhead wires. I would suggest that the trolleybuses would be ideal for cities the size of Oxford. They are clean, quiet and energy efficient, and they can run on battery power for short distances, to avoid the need to erect overhead wires along the High.

When the oil begins to run out, we shall have to turn to electric power for most forms of transport.

Martin Smith, Abingdon