Warrant Development for Signalization of Superstreet Intersections with Two or Three Approaches

Regional traffic engineers are often faced with the decision of whether to signalize non-standard intersections, but unfortunately guidance for this decision is currently lacking both in North Carolina and nationally. While signal warrants for standard intersections in the 2009 Manual on Uniform Traffic Control Devices (MUTCD), such as crash experience or coordinated signal systems, can be applied to any intersection geometry, volume specific warrants assume a four-legged intersection with vehicles approaching from each leg. This assumption cannot be applied to intersections such as superstreets (also known as synchronized streets), directional crossovers, or the meeting of two one way streets, where not every leg has both originating and receiving lanes. Without a defensible method for determining signalization needs at all intersections, North Carolina Department of Transportation (NCDOT) may be vulnerable to accusations of inefficiencies (when an unwarranted signal is installed) on the one hand or lack of safety concern (when a warranted signal is not installed) on the other. By developing and adopting a warrant for signalization of superstreet intersections with two or three approaches, NCDOT will be able to provide guidance and support to traffic engineers in their decision making process. The development of the warrant will be accomplished through the proposed tasks including a review of literature, survey of NCDOT practices as well as those around the country, and collection of data at superstreets and directional crossovers. After developing and validating the basis for the warrant, the research team will work to disseminate this information to NCDOT, municipal, and private sector interests. This is to ensure that the new warrants are understood statewide, should the warrant be accepted and implemented by NCDOT. Given the prevalence of superstreets nationally, and the lack of warrants of this kind, the research team will also provide NCDOT with a proposal which can be submitted to Federal Highway Administration (FHWA) for possible inclusion in the MUTCD. The results of this research should be practice-ready and allow NCDOT to directly implement the research products into day-to-day activities.