GAP-BASED CRITERIA FOR TRAFFIC SIGNAL WARRANTS. SESSION 11

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. This device was an electronic module designed to plug into a Streeter-Amet Traficounter. The module converted the normal operation of the Traficounter to that of detecting and counting time gaps between vehicles crossing a road tube. After this prototype gap counter had been developed, the Federal Highway Administration initiated a research study entitled "Traffic Signal Warrants From Gap Data." This FHWA project, which was conducted by JHK & Associates, resulted in the development of three candidate "gap" warrants. The rationale behind these warrants is that it is a major-street gap availability, not solely volume, which determines the necessity of a traffic control signal. Thus, the candidate signal warrants are based primarily on site-specific gap data. The usefulness of the candidate warrants in terms of their ease of application, practicality, and validity has also been evaluated. This paper summarizes the major findings of the aforementioned study. Three gap-based signal warrants are presented: a four-hour Vehicle Delay Warrant, a Peak Hour Warrant, and a Pedestrian Volume Warrant. The paper also discusses the warrants' development, the results of field evaluations of their validity, and procedures for collecting the necessary gap data. (Author)