In the past the majority of traffic calming schemes have been on residential roads. Traffic calming measures used on distributor roads need to take account of the higher flows, the higher speeds, the higher accident rates and the need to maintain capacity. TRL is assessing the effectiveness of traffic calming measures on urban distributor roads so that Driver Information and Traffic Management Division (DITM), Department of Transport (DOT) can provide advice on suitable traffic calming measures for these roads. This report describes a study of traffic calming measures at 4 sites on (1) Wych Hill Lane, Woking with a two-way flow of 12,000 vehicles per day; (2) Mayfield Road, Farnborough (8,000 vehicles/day); (8,000 vehicles/day); (3) Dedworth Road area, Windsor (11,500 vehicles/day) and (4) North Watford area (8,000 vehicles/day). The study showed that traffic calming measures including flat-topped road humps can be used on distributor roads to reduce speeds while generally satisfying bus operators, emergency services and the residents of the roads; overall the 85th percentile speeds between the humps were reduced by 11mph from 38 to 27 mph and mean speeds by 10 mph from 34 to 24 mph respectively. (A)
Abstract