CLEARLY the safety partnership must continue to think of new ways to ensure their revenue does not dry up.

Having seen a fall in income due to drivers becoming used to fixed cameras and slowing down when approaching them, they are now using mobile cameras to make up the shortfall.

What else is one supposed to presume by the decision to site mobile units on bridges across the M4.

Of course one can point to the incidence of accidents on the M4 and attempt to justify the existence of cameras but to do so ignores all the evidence.

For example the last three reported accidents involved HGVs either hitting the central reservation or moving from the inside lane to the centre lane without ensuring it was safe to undertake the manoeuvre.

I see no hint of a vehicle exceeding the 70mph speed limit being responsible for any of these incidents.

Indeed cameras set at 79mph or less will invariably only pick up motor cars or motor cycles as HGVs cannot do 75mph.

Having seen the police in action last week, I commend them for being able to deploy so many officers. It's a pity they can't find officers to undertake other duties such as apprehending real criminals.

D MORGAN

Swindon