Field evaluation of two way versus four way stop sign control at low volume intersections in residential areas

This study was conducted to acquire data that would assist in resolving the conflicting opinions and research results that exist about two-way versus four-way stop sign control at low-volume intersections in residential areas. A unique opportunity to compare operational issues at such intersections existed at a West Virginia municipality in which three intersections were regulated by two-way stop sign control during the winter months and then converted to four-way stop sign control during the summer. The experimental design was a before-and-after analysis with control intersections. Traffic volume, delay, speed, and observance data were collected, analyzed, and used to determine road user costs. Accident experience and potential legal issues were also investigated. At the three intersections studied, use of four-way stop control was found to cause unnecessary motorist delay and road user costs. A delay analysis found that the use of four-way stop control was 2.6 times less efficient than use of two-way control. Annual road user costs increased by $2,400 per intersection after installation of four-way stop control. Mean midblock vehicle speeds were not affected by the type of intersection control; however, 85th percentile speeds decreased by 2.3 mph after installation of four-way stop control. The driver observance study showed that the stop sign violation rate increased by 11 percent after installation of four-way control.