Plans to introduce toll fees on a 20-mile section of the heavily congested A14 road in the UK have hit a setback after a 100-page government study could not come up with an economically viable option.

The report by consultants Atkins said that plans to introduce tolls on the Cambridgeshire stretch, which connects Felixstowe port with the Midlands, could drive at least 35% of motorists into using local roads.

The study comes at a time when the government is trying to cope with operating and funding a key road network.

Prime Minister David Cameron commissioned the study on how to fund motorways and A-roads and explore the possibilities of privatisation due to difficulties in identifying a solution that is viable not just politically for the government but also economically for the private sector.

The government is expected to levy tolls selectively in order to shift the cost of major road improvement works to the private sector. However, the M6 toll stretch, which is currently the country’s only pay-per-use motorway, has not met expectations.

According to the study, even by levying a reasonable toll fees of £2 for cars and £4 for trucks, the scheme is likely to generate a low cost-benefit ratio of £1: £0.93. The development costs of such a scheme would be £1.1bn.

"Plans to introduce tolls on the Cambridgeshire stretch, which connects Felixstowe port with the Midlands, could drive at least 35% of motorists into using local roads."

A tolling scheme could cost up to £1 for each motor, which would erode revenues from vehicles.

There are separate plans to levy fees for any drivers using motorways and A-roads against a reduction in standard duty for using smaller roads. Though, there are concerns that this would not encourage people to use fuel-efficient vehicles.

The government also faces a problem as revenues from vehicle excise duty on cars have declined, with an increasing number of drivers using energy-efficient vehicles that are exempted from road taxes.

A Department for Transport spokesman was quoted as saying that tolls on the A14 are being considered as it can be used to transform the highway into a high-capacity corridor with widened roads, but not as a source of funding.

Tolls are likely to offer only a small portion of the required funding, with the majority of the funds being provided by both local partners and the central government.