Sir – Whenever trams are mentioned, Martin Smith rules it out for Oxford on grounds of cost and his opinion that our city is of insufficient size to generate enough demand.

However, the common view that “buses are cheap, light railways are expensive” does not stand up against the facts, as any member of Railfuture should know.

There is no intrinsic reason why a vehicle that rolls on rails should be any more expensive to operate than one that rolls on a road; quite the reverse. In fact, the railway was invented as the cheapest way to move a heavy load. The truth is that buses appear cheap only because their biggest cost is not counted. As heavy vehicles, they inflict thousands of times more wear on the road than any car.

In Oxford, they heavily outnumber trucks and so are responsible for almost all the damage. Paying little more Vehicle Excise Duty than a car and receiving more than half their fuel duty returned as a rebate, they meet only about a sixth of their track cost.

The remaining five-sixths is met by us taxpayers, whether we use a bus or not, along with many other subsidies. The loss of jobs may be lamented but there is now no more need for drivers in trams than there is unsightly overhead cables. Hiding the power supply below ground will cost more up-front, but the considerable reduction in staff required will dramatically reduce operating cost and thus profitability.

Has any recent cost/benefit analysis been carried out? Blind assumptions regarding viability which take no account of health, safety or our environment are no substitute and do no one any credit. One final benefit should also be counted: the potential economic one from a clean and quiet city centre, rendered far more accessible via a system with much greater intrinsic capacity.

Dr Ian East, Islip