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

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40 Safety Analysis In this report, researchers documented the results of multi- ple analyses focused on developing an improved understand- ing of WWD crash characteristics on divided highways as well as wrong-way countermeasure effectiveness on divided highways and freeways. An in-depth safety analysis of wrong- way crashes using a multistate dataset assessed the impact of median width and traffic control devices upon wrong-way crashes on high-speed divided highways. In addition, WWD event data were used to evaluate the effectiveness of LED border-illuminated WRONG WAY signs and red RFBs above and below WRONG WAY signs. The findings from this research effort indicate that there is no one traffic control device that can reduce wrong-way move- ments 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 analy- sis 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 (dis- cussed in Appendix B). 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 fac- tors as well. The manner in which the median width, median opening, median design, left-turn movements, and other fac- tors 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 UVC to distinguish 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 crite- rion. The safety analysis conducted in this project found that there were numerous sites in the analysis where the traffic control devices did not fully comply with the MUTCD with respect to treating the location as one or two inter sections. 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 per- cent). This finding may be an indication that practitioners are using engineering judgment to determine the most effec- tive 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 proj- ect that the criterion may be 50 ft from a safety perspective. These findings led researchers to suggest changes to the defini- tions of median width and intersection in the MUTCD. The safety analysis indicated that most wrong-way move- ments at divided highway crossings 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 documen- tation. The suggested changes to the MUTCD language focus on 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 crossroad 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 out- side of a wrong-way turn, C H A P T E R 4 Conclusion

41 – 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 WWD event data support the use of flashing red LEDs within the border of WRONG WAY signs at freeway exit ramps. Therefore, researchers suggested 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 prom- ising findings led to additional installations of the red RFB WRONG WAY systems at freeway exit ramps in central Florida. Additional data from these sites are needed before a detailed statistical analysis can be conducted and revisions for MUTCD language suggested. Suggested Revisions The findings from this research effort led to the devel- opment of proposed changes to the 2009 MUTCD (FHWA 2012). Appendix C documents the researchers’ reasoning for the changes and the detailed revisions. The following is a list of the MUTCD sections and figures included in the sug- gested revisions: • Section 1A.13—Definition for “#94, Intersection” • Section 1A.13—Definition for “#115, Median” • Section 2B.09—YIELD Sign Applications • Section 2A.23—Median Opening Treatments for Divided Highways with Wide Medians • Section 2B.32—KEEP RIGHT and KEEP LEFT Signs • Section 2B.37—DO NOT ENTER Sign – Figure 2B-12 • Section 2B.38—WRONG WAY Sign • Section 2B.40—ONE WAY Signs – Figure 2B-15 – Figure 2B-16 – Figure 2B-17 • Section 2B.41—Wrong-Way Traffic Control at Interchange Ramps • Section 2B.42—Divided Highway Crossing Signs • Section 3B.20—Pavement Word, Symbol, and Arrow Markings • Section 4C.01—Studies and Factors for Justifying Traffic Control Signals