Sir - You report on your website that the police "warned drivers" of the closure of the M40 following a crash at 3.50pm on Wednesday, December 19.

I joined the M40 at Oxford heading for London at 6pm. No such warning was in view, despite the fact that two hours had passed since the closure.

As a result, along with thousands of other drivers, I was held in a largely static tailback for four hours, reaching the High Wycombe turn-off at 10pm. Between junctions, there was no layby, no service facilities and no attempt to communicate with drivers to use the hard shoulder. The police clearly failed an elementary test of regard for public safety and duty to advise that other routes should be taken.

D. M. Downes (Prof), Wandsworth