Sir: Nigel Seymer and Carlton Reid (Letters, 10 January) take me to task over my suggestion (8 January) that vehicles capable of zero emissions will reduce congestion. The reasoning is that when such vehicles are on stream it will be feasible for towns and cities to exclude all but zero-emission vehicles from their centres. This could happen now, but with city centres in a fight to the finish with out-of-town megacentres, a zero-emissions policy could be a step too far.
Professor PETER F SMITH
Chairman, Environment and Planning Committee
Royal Institute of British Architects