GAP-BASED CRITERIA FOR SIGNAL WARRANTS

Most of the traffic signal warrants which are commonly used are based primarily on major street volume. If the volume exceeds some value for a specific period of time, then a traffic control signal is warranted, subject to other warrant criteria (e.g., side-street volume) also being satisfied. The primary factor affecting the operational perfrmance of a two-way STOP controlled intersection is not volume, per se, but the availability of gaps in the major street traffic flow. In response to the need for a practical means by which to collect site-specific gap data, the Federal Highway Administration (FHWA) sponsored the development of an automatic gap counter.