Crash data and signal coordination: A one-way pair case study

Abstract

In a coordinated, or synchronized, traffic signal system, drivers become attuned to the timing and pattern of traffic signals. Good signal coordination improves roadway efficiency and reduces delay and emissions, but drivers may speed or engage in other unsafe behavior to stay in the â??platoonâ?? of the traffic flow. Because one-way roads accommodate fewer movements than typical streets, they generally exhibit very efficient signal coordination and may therefore provide the greatest incentives for drivers to engage in unsafe behavior. To better enable analysis of crash trends and distributions, Florida's District 7, which includes the Tampa-St. Petersburg metropolitan area, loaded statewide mainframe crash data into an ESRI/Microsoft Access geodatabase. Using the geodatabase, a cross tabulation was performed showing the distribution of driver-contributing causes among roadway crash rate categories. In addition to addressing an abnormal crash distribution along a specific roadway, this study incorporates aspects of traffic records beyond crash data including traffic volume data, physical conditions, and traffic signal operations data. Review of roadway, crash, and traffic operations data have identified several issues that merit further analysis including: motorist's inability to see traffic signal heads obscured by truck trailers; heavy traffic merges and underutilization of the center lane; and potential signal-timing related red light running crashes.