This report summarises a UK project investigating whether highway design measures can be used to encourage drivers to comply with the speed limit. The project included a literature review, identification of suitable highway design measures and a study of the response of drivers to sketched street scenes including the design measures. Some participants also drove in a simulator with moving versions of some of the sketches. A number of design features reduced driving speed as assessed by the volunteers. These included the extent of buildings, parked cars along the roadside, buses and cycles within their own designated lanes, decreases in the number of traffic lanes and in carriageway width, introduction of a structure in the road, and replacing roadside lighting with lighting on a central reserve. The features that reduced assessed driving speed generally also increased driver stress. The mean assessed speed limit was high on rural roads and dual carriageways. Assessments of driving speed varied with sex, age, occupational group, annual mileage, and whether the respondent drove a company car. The effects were greatest where the road was dual carriageway or rural. Further research would ideally include more simulator and on-road sessions to test driver behaviour. An indicative design document on self-calming roads was produced for internal use within the UK Highways Agency.
Abstract