Very often Designers are required to submit speed surveys, carried out by a company approved by the Local Authority, of existing background traffic speeds in an area. This is required to determine if the required Sightlines and Forward Stopping Distances for exiting & approaching vehicles are achievable in relation to the existing traffic speeds, based on an actual speed survey.
Depending on the circumstances, the requirements for these sightlines are set out in the current relevant design standards, either the Design Manual for Urban Roads and Streets or the NRA’s Design Manual for Roads & Bridges.
NRB are qualified and experienced at undertaking comprehensive Radar Speed Surveys, and Speed Survey Reports, in order to establish both the 85%ile Traffic Speed and the Mean Traffic Speed. This is done by way of a Radar Speed Survey undertaken by qualified approved NRB staff, during off-peak traffic conditions. Qualified Staff will visit the site and undertake the speed survey, recording the results. Chartered Engineers within NRB then use this information to prepare Reports and Drawings of the required sightline and forward stopping distance based on the Radar Speed Survey Results in order to demonstrate that the development complies with the relevant Design Standards.