`Secret' vehicle activated speed limit reminder signs have been used as a means of warning drivers that they are travelling too fast by the activation of a sign triggered when the speed of the vehicle is above a preset level. This report reviews the published results from 13 of these `secret' sign sites which have been used in the UK, other European countries and the USA. Single `secret' signs were used at ten sites and a pair of `secret' signs were used at three of the sites. The main conclusions are that `secret' vehicle activated speed limit reminder signs can lead to reduced vehicle speeds of about 2 mph at the sign and some of this reduction is maintained some distance downstream. There was an encouraging 40% reduction in accidents but the accident numbers were small. Vandalism was reported as a problem at some non-UK sites. (A)
Samenvatting