Sir – It seems to have become obligatory, when ridiculing the proposal to close the city centre to through traffic, to claim some special but unspecified ability to understand The Real World.

In this Real World the mountain — the greater problem of pollution and congestion — suddenly becomes a molehill which must be tolerated because the detailed problems of how X gets from A to B and back are insurmountable.

Occasionally I have reason to drive through the city centre and while accepting that my car use is unsustainable and anti-social, I am not prepared to disadvantage myself relative to the much more affluent majority (who are paying a much smaller proportion of their total income in income and road tax).

If I gave up driving altogether I would feel overburdened and painfully conscious of the apparent irresponsibility of those who continue to drive.

If, however, the city centre closed to through traffic I would accept it and find other ways of moving the materials I sometimes need to transport, and if everyone else had to do the same, a new infrastructure of possibilities would develop. When excusing myself for failing to meet formerly unsustainable commitments, I might keep up the standard of my hypocrisy in the real world by blaming Sushila Dhall — and her Churchillian intransigence.

Susan Heeks, Oxford