Sir – In response to Dr Ian East’s letter (April 2), I did not suggest that the historic architecture of Oxford is less worthy of protection that that of cities in France, but I said that trolley buses could run under battery power for short distances, thus avoiding the need to erect overhead wires in the city centre and High Street.

Trollybuses and trams (except in Blackpool) disappeared from British streets in the 1960s. Since then, there has been a modest revival of trams in British cities, but John Prescott’s promise of 25 new trams in ten years has come to nothing.

However, there seems to have been no discussion of trolleybuses as a suitable means of public transport in cities where there is not sufficient volume of traffic to justify tramways.

Another consideration is the geography of Oxford streets. For efficient operation, trams need an unobstructed track, either in wide streets or tram-only streets.

It would not be possible to make St Clement’s or Cowley Road, for example, into tram-only streets, because there are no alternative routes for other traffic. Although trolleybuses may not have as great a capacity as trams, they are more flexible, and are clean and quiet.

Indeed, the only objection that has been made against them is that they are too quiet, so that cyclists and pedestrian do not hear them coming.

Martin Smith, Abingdon