A Devon haulage firm has backed calls to dual the entire A303 from Exeter to London.
Honiton-based Bale Group, which runs 55 lorries and employs 120 people, said it would save £25,000 a year in fuel.
Improvements would provide an alternative route to the M5 and M4 but campaigners say the plan would be devastating for the environment.
The views of businesses will be presented to the Government later this month.
The A303 is one of the most direct routes from London to Devon and Cornwall, but is renown for its bottlenecks.