Vehicles with a gross vehicle weight of more than two tonnes are restricted to 60mph on unrestricted dual carriageway roads and 50mph on single carriageway roads. The speed limit is 70mph on motorways.

The warning came after van driver Guy Litton, of Rugby, Warks, was clocked at 58mph in a 60mph zone in his Volkswagen Transporter and sent a speeding ticket. He called in to Stratford police station to ask why the ticket had been issued and was told about the rule, which is included in the Highway Code.

Litton said: ‘It’s a farce and just another cunning trick to pick the pockets of innocent motorists. If there is a different limit for different types of vehicle then it should be displayed on the roadside.’

Stephen Rumble, communications manager with Warwickshire Road Safety Reduction Partnership, admitted the rule could be confusing but said: ‘What is important is what the Highway Code says and drivers should check it regularly.’