Mr. Derek Brady:

If we were to apply speed limit reductions on motorways alone, some drivers would not have the journey time advantage they previously had and might see benefit in transferring to other single-carriageway routes without the safety benefits of motorways. If significant volumes of traffic were to transfer to single-carriageway or, as we call them, undivided roads, there would likely be an increase in accidents and fatalities. We estimated the increase in fatalities to be five per annum in the scenario in which we reduced motorway speed limits only and did not reduce speed limits on competing routes.