Britain’s most unsafe busy main road is a 23km section of the A21 between Hurst Green and Hastings in East Sussex according to the Road Safety Foundation (RSF).

In a survey of the motorways and A roads published this week the organisation said that the single carriageway section of A21 had a combination of above average risks and large numbers of road users exposed to those risks. Between 2006 and 2010 there were 77 fatal and serious crashes on the section used by 13,883 vehicles on an average day.

This compares to a 12km section of the A537 between Macclesfield and Buxton in Derbyshire which had a fatal and serious casualty rate of 53 in the same time frame but which carried significantly less daily traffic.

“Typically the highest risk roads are narrow, twisting, hilly and in the rural areas of the north. Although apparently clear candidates for priority action, their lower traffic flows may not justify the spend on improvements,” the RSF said.

RSF director Dr Joanne Marden said the foundation had decided for the first time to highlight high risk busy roads because anticipated reforms of road financing and ownership will require a new focus on measuring the safety performance of highways. It argues in the report that minimum safety levels should be set which make sense to the public, investors and new operators of Britain’s major road infrastructure.

“The planned reforms in road financing means a new focus on measuring safety performance and the high returns quickly available from safety engineering. Where there is clear evidence of higher risk and heavy traffic flows the economic case for intervention is compelling,” Dr Marden said.

“There are practical, relatively inexpensive solutions which will pay back the costs of investment in a matter of weeks – with high rates of return in the first year alone – and go on saving lives and saving money for the nation for many years to come. Much of this remedial work can be done as part of routine maintenance,” she said.

Examples of best benefit improvements are traffic signals at busy junctions, high friction surfacing and redesigned layout. “New average speed cameras and interactive speed signs feature strongly on roads that have improved the most,” the RSF said.