REGARDING the debate about Traffic-calming, you may find it strange that, as an experienced Class 1 HGV driver and motor vehicle technician, I totally agree with your frequent correspondent Adrian Shurmer on the safety aspects of traffic-calming.

But perhaps the extra pollution caused by it is of more interest to the non-motorist.

Internal combustion engines are pretty inefficient because most of their energy is lost to the atmosphere through the radiator and exhaust. At speeds below about 60mph, the amount of fuel used is therefore dependent on the time under power.

If a vehicle is forced to slow to negotiate a hump or mini roundabout and then accelerate back to the original speed, the overall fuel consumption for the distance from the start of braking to the end of accelerating is vastly increased and probably almost doubled, especially at the foot of a hill.

Also, recent research into the danger of dust pollution from vehicles shows that each time one uses its brakes, the friction linings wear and generate fine dust particles.

Tyre wear is also increased under braking and accelerating conditions and when turning sharp corners. And it is hardly surprising that dust pollution is said to be far higher near junctions.

At a time when we are looking to reduce carbon dioxide emissions, it seems rather strange that many local authorities are still introducing measures which probably increase road traffic pollution. The small-diameter roundabouts are probably the worst in this respect.

The new roundabout on the A56 at Kelbrook made my articulated vehicle use an extra two gallons of fuel per day, which averages out at about one litre for each time I crossed it.

I have also undertaken a rough mathematical calculation based on time under power which gives a similar answer.

The whole theory behind traffic-calming may not be far removed from Monty Python's Flying Circus, but even they stopped a sketch featuring gangs of marauding Keep Left bollards for being far too silly.

It all seems like a crazy race to find the ultimate 'big business' marketing challenge, by devising a new idea which is patently ridiculous, just to see how many people will be taken in and believe it, and then to see how long they can get away with it.

It may be the case that a large proportion of the population have been misled over traffic-calming and likewise the politicians, especially those with an alleged 'green' pedigree.

Traffic- calming may statistically reduce serious road accidents, but perhaps it doubles the number of people suffering from asthma and other potentially serious respiratory conditions.

G PYE, Downham Road, Chatburn, Clitheroe.

Converted for the new archive on 14 July 2000. Some images and formatting may have been lost in the conversion.