Traffic Control Devices and Measures for Deterring Wrong-Way Movements (2018)

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1 S U M M A R Y In this report, researchers document the results of multiple analyses focused on devel- oping an improved understanding of wrong-way driving crash characteristics on divided highways, as well as wrong-way countermeasure effectiveness on divided highways and free- ways. An in-depth safety analysis of wrong-way crashes using a multistate dataset assessed the impact of median width and various traffic control devices upon wrong-way crashes on high-speed divided highways. In addition, wrong-way driving event data were used to evaluate the effectiveness of light-emitting diode (LED) border-illuminated WRONG WAY signs and red rectangular flashing beacons (RFBs) above and below WRONG WAY signs. All of the research findings were then used to develop suggestions for changes to the 2009 Manual on Uniform Traffic Control Devices (MUTCD) (2009 MUTCD with Revisions 1 and 2, FHWA 2012). The findings from this research effort indicate that there is no one traffic control device that can reduce wrong-way movements across all of the circumstances studied (i.e., high- speed rural divided highways, high-speed urban divided highways, and freeways). In addition, the fidelity of the safety analysis did not allow researchers to assess the overall impact of the various combinations of traffic control devices. However, researchers were able to identify several traffic control devices that may be effective in reducing wrong-way movements on high-speed divided highways and freeways. In addition, the research team addressed several inconsistencies with regard to wrong-way movement traffic control in the MUTCD. There are many factors that impact the operation of a divided highway crossing as one or two intersections. The median width is an important factor, but there are other factors as well. The manner in which the median width, median opening, median design, left-turn movements, and other factors interact could have a significant effect on the potential for wrong-way movements and were beyond the scope of this research project to analyze. The 30-ft criterion used in the MUTCD and the Uniform Vehicle Code (UVC) to distin- guish crossing functions as one or two intersections has existed since at least the mid-1940s. However, there is no known rational basis for the use of 30 ft as the threshold criterion. The safety analysis conducted in this project found that there were numerous sites in the analy- sis where the traffic control devices did not fully comply with the MUTCD with respect to treating the location as one or two intersections. Primarily, this was represented in narrow medians (less than 30 ft) with STOP or YIELD signs in the median opening (6 percent) or in wide medians (greater than or equal to 30 ft) with no STOP or YIELD signs in the median opening (26 percent). This finding may be an indication that practitioners are using engineering judgment to determine the most effective installation of interior right-of-way devices to address safety and operations at divided highway crossings. There is also evidence from the safety analysis conducted in this project that the criterion may be 50 ft from a safety Traffic Control Devices and Measures for Deterring Wrong-Way Movements

2 perspective. These findings led researchers to suggest changes to the definitions of median width and intersection in the MUTCD. The safety analysis indicated that most wrong-way movements at divided highway cross- ings occurred when the driver turned left into the near-side roadway traveling in the wrong direction. The data indicated that this maneuver occurred for 90 percent of the wrong-way crashes for which the wrong-way entry point was specifically identified in crash documenta- tion. Therefore, the suggested changes to the MUTCD language focus upon addressing this maneuver. Additional specific findings from the safety analysis pertinent to the suggested changes to the MUTCD language include the following: • Greater use of ONE WAY signs (above those that are required) does not appear to deter wrong-way movements. • There was limited evidence that use of the required divided highway sign on the cross- road exterior approaches deters wrong-way movement. • The placement of DO NOT ENTER and WRONG WAY signs on the inside turn of a wrong-way movement (side of divided highway nearer the right-of-way line) does not deter wrong-way movements. • Treatments that appear to deter wrong-way movements include: – DO NOT ENTER and WRONG WAY signs on the outside of a wrong-way turn, – Wrong-way arrow markings for the through lanes on the divided highway, – Presence of a centerline in the median opening, and – Use of stop or yield lines when interior right-of-way treatments are provided. Separate analysis of wrong-way driving event data supported the use of flashing red LEDs within the border of WRONG WAY signs at freeway exit ramps. Therefore, researchers sug- gest changes to the MUTCD to allow red LEDs within the border of WRONG WAY signs. Early results from the red RFB WRONG WAY sign system pilot found that most of the errant drivers self-corrected before reaching the main lanes. These promising findings led to additional installations of the red RFB WRONG WAY systems at freeway exit ramps in cen- tral Florida. Additional data from these sites are needed before a detailed statistical analysis can be conducted and MUTCD language suggested.