Question to the Department for Transport:

To ask the Secretary of State for Transport, whether the average accident rate is higher on dual carriageways than on three lane roads.

The Department does not hold any information on the number of lanes in either the road accident data supplied by police forces or road traffic estimates. Therefore it is not possible to provide a comparison between dual carriageway roads and single carriage roads with three lanes.

However, the Department does record the number of carriageways at the scene of accidents as well as the length of ‘A’ roads by number of carriageways. As a guide, in 2015 for Great Britain there were 380 reported personal-injury accidents per billion vehicle miles on single carriageway ‘A’ roads and 140 accidents per billion vehicle miles on dual carriageway ‘A’ roads.