The 'following too closely' (ftc) monitor system is an experimental device designed to measure vehicle gaps at a point along the highway and to advise the motorist, by means of a flashing message on a sign, that he is following the car in front of him too closely. On October 31, 1974, ten ftc monitors were installed at four sites on a 6-mile 4-lane undivided section of route 1 in Woodbridge, Virginia. As the ftc system is a new concept in highway safety, an investigation was conducted to evaluate the effects of the system on vehicle spacings, speeds, and accidents. Traffic and accident data were collected for a period 1 year before and 1 year after the monitors were installed. The results of the study reveal that use of the ftc system resulted in a significant reduction in accidents. A decrease in injury, property damage, and all crash types, including rear end collisions, was found. Monitors located in a suburban area, within a 0.5-mile section downstream from traffic signals, were found to be more effective in reducing incidences of following too closely and accidents than were monitors in rural areas..
Abstract