Motorists are eight times more likely to be badly injured on single-lane A-roads than on motorways, research shows.
A new report found that the risk factor was significantly higher on single carriageways because of the lack of lay-bys and crash barriers as well as the presence of dangerous junctions.
The study found that 18 per cent of the busiest roads had an “unacceptably high risk”, up from 14 per cent a year earlier. Researchers also identified the ten most dangerous stretches of roads in Britain and found that all were single carriageway A-roads.
The A18 between Laceby and Ludborough, Lincolnshire, was found to be the most dangerous road, with 17 fatal or serious crashes between 2011 and 2013 on a 16km (ten-mile) stretch, up from ten in the previous three-year period.
The A36 at Totton, west of Southampton, was the second worst road, with 17 deaths on a 6km stretch, up from 12 in the previous three years. Other blackspots include the A44 between Llangurig and Aberystwyth, in mid-Wales, and the A532 in Crewe.
The Road Safety Foundation, which published the report, said that A-roads should be given a greater share of funding to address urgent safety concerns.
Lord Whitty, chairman of the foundation, said: “On many A-roads, the margin for human error is often small. The largest single cause of death is running off the road, where poor roadside protection can see brutal impacts.”
For motorways, 95 per cent of the network was deemed low risk and 5 per cent low-medium risk. For dual carriageways, 25 per cent were low risk and 75 per cent low-medium risk. No part of the single carriageway network was considered low risk.
The report comes weeks before Highways England, which is responsible for maintaining England’s strategic roads network, publishes a blueprint to reduce accidents. Its goal is to ensure that the serious accident rate on major roads is “close to zero” by 2040.
A Highways England spokesman said the organisation had pledged that 90 per cent of its roads would have the highest safety ratings by 2020, adding: “England’s motorways and major A-roads are some of the safest in the world but we are committed to improving safety even further.”