The research, by the Highways Agency and the county council, was done on the A5 between Telford and Shrewsbury from 1600 BST to 1900 BST on Tuesday.

John Clayton, the vice chairman of Shropshire's Chamber of Commerce, said he was delayed for two meetings and accused the council of being "arrogant" for holding the survey during rush hour.

But the authority said it had about �50m to spend on transport over the next five years and it needed to do the survey to help it spend the money wisely.

Martin Withington, a council road planning engineer, said: "We apologise for the delays that this type of information collection causes, but we feel it is very necessary to do it.

"In the same way as it is necessary to maintain the roads, it's also very necessary to collect information about travel so that we can plan for transport properly.

"It is a delay, it's unfortunate, it's frustrating. I've been in lots of queues in motorways all around the country - I know how frustrating it is."

It is the second time the council has carried out such a survey in six months.