I am replying to the letter headed “Think of the driver” (The Argus, April 3) from Mr Docherty of Southwick, who wanted to know how driving at 20mph is environmentally friendly, and made further observations.

Fast traffic is a powerful disincentive to walking and cycling. Slower speeds help to civilise the streets so that people on foot or on bikes (or in wheelchairs) are not deterred from going out and about, and the general ambience of the area is improved.

By encouraging active travel (instead of using motor vehicles), our health and the environment will benefit massively in the longer term.

The frequent need for motor vehicles to stop and start in urban settings needs to be taken into account in any calculations of fuel consumption and emissions.

A study from Imperial College, London, last year found that PM10 emissions were lower for both petrol and diesel vehicles at 20mph compared with 30mph. More research needs to be done but the report concluded that the effects of 20mph speed limits on vehicle emissions are mixed.

In his speculation on the causes of accidents, Mr Docherty refers to cyclists being able to stop in the space of two feet. This is often impossible. Sudden braking can result in the bike stopping and the cyclist continuing to travel forward (ie, without the bike).

The lengthy stopping distance of motor vehicles at higher speeds is another good reason why motor vehicle speeds should be lower in urban and residential areas.

As a cyclist I’ve experienced many incidents with motor vehicles. I’ve been knocked off twice in broad daylight. It was not my fault on either occasion. I’ve also been run off the road by a left-turning vehicle and doored as a motorist opened a car door without looking. Once, a car pulled up on my right foot as I waited at a red light in London Road.

Many cyclists prefer to wear bright and reflective hi-vis clothing to increase their visibility on the roads and road safety advice strongly endorses this. Lycra is just a comfy, quick-drying fabric suitable for all kinds of activity.

It is incomprehensible that anyone who is seriously concerned about transport issues should object to practical dress options.

Becky Reynolds, Bricycles