This report describes trials of speed limit "Roundels" and "Count-down" signs. The main trial described was a collaborative trial between TRL, Northumberland County Council and the County Councils of the DOT Eastern Region. A summary of the results of two small trials in Powys and Buckinghamshire is also given. The work was carried out as part of a project to develop and investigate low-cost safety engineering measures for the Department of Transport, Road Safety Division. In 1992, 30 mph "Roundels" or "Count-down" signs were installed at various villages in the DOT Eastern Region. During 1993, Count-down signs were installed in Northumberland. The objective of the trial was to alert drivers to the presence the presence of a speed limit and thus to reduce the speed of vehicles within the villages. The 40 mph Roundel markings produced a reduction in mean speed of about 3 mph which was statistically significant. The 30 mph Roundels and Count-down signs did not have a significant effect on mean speeds. Despite the small size of the trials, injury accident data were considered. The accident frequencies were very low and there was insufficient evidence to draw any firm conclusions regarding any accident benefits following measure installation. (A)
Abstract