Study Details

Study Title: Safety Evaluation of Signalized Restricted Crossing U-Turn Intersections

Authors: Hummer & Rao

Publication Date: DEC, 2017

Abstract: This study evaluated restricted crossing U-turn (RCUT) intersection and was conducted by the DCMF program for the Evaluation of Low-Cost Safety Improvements Pooled Fund Study. RCUT is defined as a three-approach or four-approach intersection where minor street left-turn and through movements (if any) are rerouted to one-way downstream U-turn crossovers. RCUTs are also known as superstreets, J-turns, reduced conflict intersections, and synchronized streets. Previous research has shown that unsignalized RCUTs are generally safer than conventional options. However, there are no known studies specific to the safety of signalized RCUTs. The objective of this effort was to collect and analyze crash data to develop a crash modification factor (CMF) for signalized RCUTs. This study collected and analyzed crash data before and after conversion of 11 intersections from conventional to RCUT design. The intersections were in suburban areas on four- or six-lane arterials. For most individual sites and groups of sites examined, odds ratio tests showed that there were high-quality comparison sites available, and regression to the mean was not an issue. The project team recommends a CMF of 0.85 for overall crashes and 0.78 for injury crashes for the conversion of a conventional intersection to an RCUT intersection. Based on those CMFs, the project team produced an estimated benefit-to-cost ratio of 3.6 to 1.0 when considering safety and operations or 2.6 to 1.0 considering safety only.

Study Citation: Hummer, J.E., and S. Rao. "Safety Evaluation of a Signalized Restricted Crossing U-Turn." Report No. FHWA-HRT-17-082. Federal Highway Administration. McLean, Virginia. (December 2017).

Study Report: Download the Study Report Document


CMFs Associated With This Study

Category: Intersection geometry

Countermeasure: Convert a conventional signalized intersection to a signalized superstreet

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.85 15 4 Stars All All Principal Arterial Other Suburban
0.78 22 4 Stars All K,A,B,C Principal Arterial Other Suburban