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. I have often driven miles with police cars behind me and never once have I been stopped or warned. If there is a different limit for different types of vehicle then it should be displayed on the roadside. I know ignorance of the law is no excuse but there are so many obscure ones that the man in the street can’t possibly be expected to know them all.’

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.’

Many drivers of large panel vans will be aware of the rule, but what may not be so well-known is the fact that the Ford Transit Connect also weighs in at just over two tonnes, unlike its rivals, the Citroen Berlingo, Renault Kangoo et al. Thus Transit Connect drivers are only allowed to travel at 50mph on 60mph roads and at 60mph on dual carriageways.