I believe that it is your correspondent Jo Pedrette (Hooray for humps', Times Letters, April 25) who has made the error about road humps bringing about a better and safer environment.

There is well-founded evidence that wherever humps are introduced airborne pollution increases because they bring about driving techniques which result in the car engine operating well below optimum efficiency.

I would much rather rely on my own ability to judge when and where to cross the road safely than suffer permanent breathing problems because of somebody else's harebrained idea for bringing about safer roads.

I also drive a Mini and negotiating humps at any speed is a tortuous and painful process.

So far as safety is concerned, I believe that I am giving less attention to pedestrians and other road users because of my efforts to avoid having the sump removed from my vehicle by these 'safety' devices.

Maurice Beales

Oulton Crescent, Potters Bar