I TOO have observed traffic slowing down in Wiltshire and elsewhere (letters, August 7). I think most vehicles exceed the 30mph limit inadvertently, being distracted by other speeding drivers, listening to a radio, talking on a mobile phone, etc.

These signs seem a relatively painless and, I guess, cheap alternative to speed cameras as part of a strategy to slow down speeding traffic. Does anyone have any data on their effectiveness?

W L RICHARDSON

Centurion Way, Credenhill.