This report describes the methods that have been used to estimate the casualty reductions that might be expected to arise from a number of potential road safety intervention options raised for consideration as part of the work by the Department for Transport in preparation of a road safety strategy post 2010.
The options are presented in four groups defined by the level of detail of the estimation: options taken to full cost benefit analysis; options taken to partial cost benefit analysis; options with quantitative casualty benefit estimates and options with qualitative casualty benefit estimates.
The report describes in detail the analytical methods used to estimate the costs and benefits associated with the list of potential options. Costs and benefits addressed include implementation, casualty savings, journey time, emissions and fuel use.
Net present values have been estimated for four potential road safety options in the first group: reduce the national speed limit on single carriageway roads without median barriers to 50mph; maintain the national motorway speed limit at 70mph and improve compliance using average speed cameras; use 20 mph zones in metropolitan residential areas more widely and increase investment in road safety engineering.