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

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B-1 the median width is measured. The first formal definition of median was incorporated into the 1961 MUTCD (Bureau of Public Roads 1961), but it did not include a description of how to measure the median width. The current definitions for median and traveled way were first introduced in the 2000 MUTCD (FHWA 2001). Similarly, the Green Book (AASHTO 2011) defines the median width as the distance between the edges of the trav- eled way in opposing directions, including the width of the left shoulders. In addition, the traveled way is defined such that it excludes shoulder and bicycle lanes. While not explic- itly stated, both National Cooperative Highway Research Program (NCHRP) Report 375 (Harwood et al. 1995) and NCHRP Report 650 (Maze et al. 2010) researchers interpreted the Green Book median width definition to include median turn lanes. The research team believes that this interpretation is based on several other statements and figures regarding the median and median width measurement in the Green Book. One of the principal functions of medians listed in the Green Book is to provide space for speed changes and storage of vehicles turning left or making U-turns. Further- more, several figures in the Green Book show the median left-turn lane included in the median width measurement. Considering human factors, it is logical to assume that median width (however measured) would be a pertinent fac- tor in wrong-way movement crashes on divided highways. As the median width increases, the ability of drivers to determine whether the intersecting roadway is divided or undivided becomes more difficult, especially at night. Thus, wider medi- ans may increase the potential for driver error that leads to a wrong-way movement. This notion is supported by the Green Book, which states that when drivers on the intersecting road- way cannot readily see the far side of the divided highway, it may hinder their ability to recognize the roadway is divided. When wider medians are used, the Green Book recommends that signing and visual cues be provided to discourage wrong- way movements. Introduction The 2009 Manual on Uniform Traffic Control Devices with Revision Numbers 1 and 2 (FHWA 2012) contains informa- tion regarding the installation of DO NOT ENTER, WRONG WAY, ONE WAY, and other regulatory signs, as well as pave- ment markings, to deter wrong-way movements at inter- sections on divided highways and at exit ramps on freeways. However, inconsistencies between the 2009 Manual on Uni- form Traffic Control Devices (MUTCD), other manuals, and state practice have been identified. In order to gain a better understanding of these issues and the MUTCD sections applicable to this research effort, the research team reviewed the 2009 MUTCD and identified material that may need to be revised based on this project’s research findings. The research team then reviewed past MUTCDs and National Commit- tee on Uniform Traffic Control Devices (NCUTCD) meet- ing documentation to gain a historical perspective of the current guidelines. The research team also reviewed current and past editions of the Uniform Vehicle Code (UVC) and the AASHTO Policy on Geometric Design of Highways and Streets (also known as the Green Book). MUTCD Language Review Definitions According to Section 1A.13 in the 2009 MUTCD, the median is “the area between two roadways of a divided high- way measured from edge of traveled way to edge of traveled way” (FHWA 2012). The traveled way is defined as “the por- tion of the roadway for the movement of vehicles, exclusive of shoulders, berms, sidewalks, and parking lanes” (FHWA 2012). In addition, the median definition states that “the median excludes turn lanes,” and that “the median width might be different between intersections, interchanges, and at opposite approaches of the same intersection” (FHWA 2012). Figure B-1 contains MUTCD Figure 2B-15, which shows how A P P E N D I X B MUTCD Review

B-2 In the 2009 MUTCD, the selection of proper wrong-way traffic control at divided highway intersections depends on whether the crossing is considered a single intersection or two separate intersections. Currently, median width is the only criterion used to make this decision. The definition of intersection in Section 1A.13 of the 2009 MUTCD states that when two roadways are 30 ft or more apart, each crossing must be considered a separate intersection. Section 2A.23 of the 2009 MUTCD further indicates that the median width used to determine the number of intersections at a divided highway crossing should be measured at the median open- ing. A review of the MUTCD’s history shows that the 30-ft median width threshold first appeared in the 1948 MUTCD (Public Roads Administration 1948). Furthermore, the inter- section definition in the 1948 MUTCD appears to be iden- tical to the intersection definition in the 1944 UVC (Public Roads Administration 1945). According to the NCHRP 375 Report, it is generally believed that the 30-ft median width threshold was based on state agency practice at the time. The Green Book indicates that most median widths range from 4 to 80 ft. Furthermore, the Green Book states that median widths less than 25 ft wide should be avoided because drivers may stop in the median with part of their vehicle unprotected from through traffic. Wider medians may be needed at these intersections for school buses and large tractor-trailer trucks (50 ft and 80 ft, respectively). These statements led NCHRP Report 650 researchers to conclude that if the 30-ft MUTCD median width threshold was based on vehicle storage requirements, it did not agree with the Green Book. Furthermore, the authors of NCHRP Report 650 recommended that the basis for the MUTCD 30-ft median width threshold be explained. Source: FHWA. Figure B-1. MUTCD Figure 2B-15: ONE WAY signing for divided highways with median widths of 30 feet or wider.

B-3 More recently, Khazraee and Hawkins (2015) examined the fundamental issues associated with the function of treating a divided highway crossing as one or two intersections. These researchers determined that the main shortcoming of the MUTCD criterion relates to the definition and measurement of the median width at the intersection, as well as the lack of consideration of the interaction of opposing left turns in the median and the median opening length. These researchers recommended that the median width be redefined as the dis- tance from the inside of the left-turn lane in one direction to the inside of the left-turn lane in the opposing direction. Therefore, the median width would not vary on opposite approaches of the same intersection. Using this modified definition of the median width and accounting for the median opening length, Khazraee and Hawkins (2015) used the Green Book minimum turning paths to develop a set of minimum requirements for control- ling divided highway crossings as one or two intersections. The results showed that, in most cases, the 30-ft median width threshold was not adequate as the sole criterion and usually underestimated the actual requirements for opera- tion as two separate intersections. The researchers suggested that the 30-ft threshold be removed and replaced with a fig- ure that provides guidance on the appropriate control at a divided highway intersection based on the modified median width and median opening length. Essentially, this guidance treats a divided highway crossing as a single intersection only if the geometry provides for simultaneous opposing left turns (i.e., in front of each other). The crossing is considered to be two separate intersections only if the geometry provides for interlocking opposing left turns (i.e., behind one another). The researchers also suggested that the MUTCD criteria include guidance about site-specific conditions, such as area type (e.g., urban or rural). The lack of a consistent median width definition makes it difficult for practitioners to uniformly use and apply the stan- dards and guidance found in the MUTCD and Green Book. In addition, questions have been raised as to the appropriate- ness of the median width threshold used in the MUTCD to determine whether a crossing at a divided roadway is consid- ered a single intersection or two separate intersections. Wrong-Way Traffic Control at Divided Highways As indicated previously, selection of proper wrong-way traffic control at divided highway intersections depends on whether the median width is greater than or equal to 30 ft or less than 30 ft. Several figures in Section 2B of the 2009 MUTCD show the signing at crossings on divided highways based on the 30-ft median width threshold. Various versions of these figures have existed in the MUTCD since the 1978 edition. For median widths 30 ft or wider, the interior approaches in the median should be controlled with STOP or YIELD signs (see Figure B-1). Divided highway crossing signs are required on unsignalized minor street approaches when both left and right turns are permitted on a divided highway unless the divided highway has an average annual daily traffic less than 400 and a speed limit of 25 mph or less. These required signs are to be located on the right-hand side of each minor street approach and mounted beneath a STOP or YIELD sign or on a separate support. Optional divided highway crossing signs can be installed on the left-hand side of each minor street approach (although these optional signs are not shown in MUTCD Figure 2B-15; see Figure B-1). The divided high- way crossing sign is intended to advise minor street users that they are approaching an intersection with a divided highway. ONE WAY signs are also required on the near right and far left corners of each intersection. Additional ONE WAY signs may be added on the far right corners of each intersection. Figure 2B-12 in the 2009 MUTCD (see Figure B-2) shows the location of DO NOT ENTER and WRONG WAY signs for median widths 30 ft or wider. However, this figure does not depict which signs are required and which signs are optional. The text in Section 2B.37 of the 2009 MUTCD states that the DO NOT ENTER sign should be mounted on the right- hand side of the road directly in view of road users that might wrongly enter a divided highway. A second DO NOT ENTER sign can be installed on the left-hand side of the road, espe- cially when traffic approaches from an intersecting roadway. However, since the required and optional signs are not shown in the figure, the determination of the left-hand and right- hand side of the road is ambiguous (i.e., are the sign locations in reference to the correct direction of travel or the wrong direction of travel?). The text in Section 2B.38 of the 2009 MUTCD indicates that WRONG WAY signs may be used to supplement DO NOT ENTER signs. While the 2009 MUTCD states that WRONG WAY signs should be placed farther from the cross- road than DO NOT ENTER signs, it too does not indicate on which side of the road. The research team believes that since WRONG WAY signs supplement DO NOT ENTER signs, it is implied that both signs would be located on the same side of the road. However, language should be added to clarify the location of WRONG WAY signs relative to DO NOT ENTER signs. In addition, an optional designation should be noted adjacent to all WRONG WAY signs in MUTCD Figure 2B-12. For median widths less than 30 ft, the 2009 MUTCD con- tains a figure for conventional left-turn lanes (see Figure B-3) and separated (offset) left-turn lanes (see Figure B-4). In both cases, there is no control on the interior approaches. However, either KEEP RIGHT or ONE WAY signs are required.

Source: FHWA. Figure B-2. MUTCD Figure 2B-12: locations of wrong-way signing for divided highways with median widths of 30 feet or wider. Source: FHWA. Figure B-3. MUTCD Figure 2B-16: ONE WAY signing for divided highways with median widths narrower than 30 feet.

B-5 Section 2B.40 notes that if KEEP RIGHT signs are used, they should be placed as close as possible to the ends of the median and should be visible to traffic on the divided highway and the crossroad. If ONE WAY signs are used, they must be placed on the near right and far left corners of the intersec- tion and be visible to each crossroad approach. Additional ONE WAY signs may be added on the far right corners of the intersection. However, the MUTCD figures do not distin- guish between required and optional ONE WAY signs when KEEP RIGHT signs are not installed. In addition to signage, lane-use arrows should also be placed near the downstream end of the offset left-turn lanes. Interestingly, both MUTCD figures for median widths less than 30 ft reference MUTCD Figure 2B-12 (see Figure B-2) for the placement of DO NOT ENTER and WRONG WAY signing, even though this fig- ure is for medians 30 ft or wider. Language referencing the application of KEEP RIGHT signs for deterring wrong-way movements at divided highway crossings should be added to Section 2B.32 (KEEP RIGHT and KEEP LEFT signs). A survey of highway agencies documented in NCHRP Report 375 (Harwood et al. 1995) found that in the 1990s, current practice was to use no traffic control in the median where the median width was less than 30-ft wide (i.e., treated as one intersection). At medians more than 85-ft wide, agen- cies consistently treated the two roadway crossings as sepa- rate intersections and controlled the interior approaches in the median with STOP signs. However, the types of control used at intersections where the median width ranged from 30 to 85 ft consisted of STOP signs, YIELD signs, or no con- trol for the interior approaches in the median. This variation in control demonstrated that median widths greater than or equal to 30 ft are not always signed as two intersections. It should be noted that for NCHRP Report 375, the median width included left-turn lanes (if present). In 2010, NCHRP Report 650 (Maze et al. 2010) included recommendations for the addition of several figures to illus- trate regulatory signing and pavement markings for a vari- ety of conditions, as well as revisions to existing figures, to address identified inconsistencies and insufficiencies. While some of these recommendations were incorporated into the 2009 MUTCD, many issues still remain. In addition, it is unknown whether the figures and/or text need to address other characteristics such as speed (low or high) and setting (urban or rural). Source: FHWA. Figure B-4. MUTCD Figure 2B-17: ONE WAY signing for divided highways with median widths narrower than 30 feet and separated left-turn lanes.

B-6 Wrong-Way Traffic Control at Interchange Ramps The 2009 MUTCD also contains information regarding wrong-way traffic control at interchange ramps in Section 2B.41. This section was first included in the 1978 MUTCD (FHWA 1978) and was located in Chapter 2E until the 2009 MUTCD. Figure B-5 contains MUTCD Figure 2B-18, which shows an example application of regulatory sign- ing and pavement marking at an exit ramp termination to deter wrong-way entry. When an interchange exit ramp intersects a crossroad such that a wrong-way entry could inadvertently be made, the 2009 MUTCD text states that the following signs shall be used: • At least one ONE WAY sign for each direction of travel on the crossroad. These signs must be placed at the intersec- tion of the exit ramp and the crossroad. • At least one DO NOT ENTER sign conspicuously placed near the downstream end of the exit ramp in full view of a road user starting to make a wrong-way maneuver from the crossroad. • At least one WRONG WAY sign on the exit ramp facing a road user traveling in the wrong direction. Additional ONE WAY, DO NOT ENTER, and WRONG WAY signs may be placed as shown in Figure B-5. However, all of the ONE WAY signs in MUTCD Figure 2B-18 are denoted as being optional, even though the text requires at least one ONE WAY sign in each direction. Furthermore, Figure B-5 shows the optional use of movement prohibition signs (R3-1 and R3-2) on the crossroad approaches to the intersection with the exit ramp. Yet, these signs are not discussed in Sec- tion 2B.41. The 2009 MUTCD text also provides the option of using freeway entrance signs (Section 2D.46) to deter wrong- way movements. The option to lower DO NOT ENTER and/or WRONG WAY signs was first introduced in the 2009 MUTCD, although this technique has been used in California since the 1970s. At locations where there are no parked cars, pedestrian activity, or other obstructions (e.g., snow, veg- etation, guardrail) and an engineering study indicates that lowering the mounting height would address wrong-way movements at freeway exit ramps, DO NOT ENTER and/or WRONG WAY signs may be installed at a minimum mount- ing height of 3 ft. However, some agencies question the use of this minimum mounting height, preferring 2 ft. Based on NCUTCD documentation in 2006, at least three states had adopted the practice of lowering the mounting height of DO NOT ENTER and WRONG WAY signs. Some states used 2 ft, while others utilized 4 ft to accommodate snow removal. The NCUTCD documentation also included an FHWA Resource Center recommendation for a minimum mount- ing height of 3 ft when all other engineering options have been tried or considered. Recognizing the visibility benefits of the lowered sign height while also acknowledging concerns over their breakaway characteristics, the NCUTCD recom- mended a minimum mounting height of 3 ft. Source: FHWA. Figure B-5. MUTCD Figure 2B-18: example application of regulatory signing and pavement markings at an exit ramp termination to deter wrong-way entry.

B-7 In addition to signage, the following pavement markings may be used to deter wrong-way movements at interchange ramps: • Double solid yellow lines should be used as a centerline for an adequate distance on both sides of the crossroad approaching the intersection with the exit ramp. • Lane-use arrows in each lane of the exit ramp should be located near the intersection with the crossroad to indi- cate permissive direction of travel (see Figure B-6). Lane- use arrows may also be used on the crossroad near the intersection. • Wrong-way arrows may be placed upstream from the ramp terminus and/or near the crossroad intersection to indicate the correct direction of travel. Wrong-way arrows may be pavement markings or bidirectional red-and-white raised pavement markers that show red to wrong-way drivers and white to right-way drivers (see Figure B-6). Guidance is also provided for interchange entrance ramps. When an entrance ramp merges with a through roadway and the design of the interchange does not make the direction of traffic evident, a ONE WAY sign should be placed on each side of the through roadway near the ramp merge point (see Fig- ure B-7). MUTCD Figure 2B-19 also allows for the optional use of wrong-way arrows and a movement prohibition sign. Language in Section 2B.41 of the 2009 MUTCD also allows other standard warning or prohibitive methods and devices to be installed to deter wrong-way movement where engineer- ing judgment determines that a special need exists. However, Paragraph 7 refers to the same section in which it is located (2B.41) for more information about wrong-way movements at at-grade intersections on expressways. Previous editions of the MUTCD referenced the WRONG WAY sign section (2B.38). Summary In order to gain a better understanding of the current traf- fic control device standards, guidance, and options related to wrong-way traffic control at divided highway crossings and at exit ramps on freeways, the research team reviewed the 2009 MUTCD. The research team also reviewed past editions of the MUTCD to gain a historical perspective of the cur- rent language and compared the current language to other resources to identify potential conflicts. Through this process, the research team identified several issues with existing lan- guage and figures. These items are summarized in Table B-1. Figure B-6. MUTCD Figure 3B-24: examples of standard arrows for pavement markings. (continued on next page)

B-8 Figure B-6. (Continued). Source: FHWA. Source: FHWA. Figure B-7. MUTCD Figure 2B-19: example of application of regulatory signing and pavement markings at an entrance ramp terminal where the design does not clearly indicate the direction of flow.

B-9 References AASHTO. 2011. A Policy on Geometric Design of Highways and Streets, Sixth Edition. Washington, D.C. Bureau of Public Roads. 1961. 1961 Manual on Uniform Traffic Control Devices. U.S. Department of Commerce, Washington, D.C. FHWA. 1978. 1978 Manual on Uniform Traffic Control Devices. U.S. DOT, Washington, D.C. FHWA. 2001. 2000 Manual on Uniform Traffic Control Devices with Revision Number 1. U.S. DOT, Washington, D.C. FHWA. 2012. 2009 Manual on Uniform Traffic Control Devices with Revision Numbers 1 and 2. U.S. Department of Transportation, Washington, D.C. Harwood, D. W., M. T. Pietrucha, M. D. Wooldridge, R. E. Brydia, and K. Fitzpatrick. 1995. NCHRP Report 375: Median Intersection Design. Transportation Research Board, Washington, D.C. Khazraee, S. H., and H. G. Hawkins, Jr. 2015. “Criteria for Determin- ing Number of Intersections at Divided Highway Junctions: Rec- ommended Changes to the Manual on Uniform Traffic Control Devices.” Transportation Research Record: Journal of the Transpor- tation Research Board, No. 2492, Transportation Research Board, Washington, D.C., p. 23. Maze, T. H., J. L. Hochstein, R. R. Souleyrette, H. Preston, and R. Storm. 2010. NCHRP Report 650: Median Intersection Design for Rural High-Speed Divided Highway. Transportation Research Board, Washington D.C. Public Roads Administration. 1945. 1944 Uniform Vehicle Code. National Committee on Uniform Traffic Laws and Ordinances, Washington, D.C. Public Roads Administration. 1948. 1948 Manual on Uniform Traffic Control Devices. Washington, D.C. 2009 MUTCD Section/Figure Identified Issue Section 1A.13—Definitions of Headings, Words, and Phrases in the Manual Lack of a consistent median width definition between the MUTCD and Green Book. Section 1A.13—Definitions of Headings, Words, and Phrases in the Manual Appropriateness of the 30-ft threshold median width to determine whether a crossing at a divided highway is considered a single intersection or two separate intersections. Section 2B.32—Keep Right and Keep Left Signs (R4-7, R4-8) Need to reference Section 2B.40 for wrong-way applications. Section 2B.37—DO NOT ENTER Sign (R5-1) Ambiguity surrounding the side of the road for required and optional signs. Section 2B.38—WRONG WAY Sign (R5-1a) Ambiguity surrounding the side of the road for signs. Figure 2B-12—Locations of Wrong-Way Signing for Divided Highways with Median Widths of 30 Feet or Wider Does not indicate which DO NOT ENTER and WRONG WAY signs are required and which signs are optional. There is no figure for the location of DO NOT ENTER and WRONG WAY signs for median widths narrower than 30 ft. Figure 2B-15—ONE WAY Signing for Divided Highways with Median Widths of 30 Feet or Wider Optional divided highway crossing sign on left- hand side of each minor approach is not shown. Figure 2B-16—ONE WAY Signing for Divided Highways with Median Widths Narrower Than 30 Feet The notes reference Figure 2B-12, which is for median widths 30 ft or wider. There is no figure for the location of DO NOT ENTER and WRONG WAY signs for median widths narrower than 30 ft. Legend implies that all ONE WAY signs are required if KEEP RIGHT signs are not used. However, Section 2B.40 indicates that only two of the ONE WAY signs are required and one is optional. Figure 2B-17—ONE WAY Signing for Divided Highways with Median Widths Narrower Than 30 Feet and Separated Left-Turn Lanes The notes reference Figure 2B-12, which is for median widths 30 ft or wider. There is no figure for the location of DO NOT ENTER and WRONG WAY signs for median widths narrower than 30 ft. Legend implies that all ONE WAY signs are required if KEEP RIGHT signs are not used. However, Section 2B.40 indicates that only two of the ONE WAY signs are required and one is optional. Section 2B.41—Wrong-Way Traffic Control at Interchange Ramps Paragraph 7 refers to the same section in which it is located (2B.41). Previous editions of the MUTCD referenced 2B.38. Figure 2B-18—Example Application of Regulatory Signing and Pavement Markings at an Exit Ramp Termination to Deter Wrong-Way Entry All of the ONE WAY signs are noted as optional even though the text in Section 2B.41 requires at least one ONE WAY sign in each direction. Figure 2B-18—Example Application of Regulatory Signing and Pavement Markings at an Exit Ramp Termination to Deter Wrong-Way Entry Figure shows optional use of movement prohibition signs, but these signs are not discussed in text in Section 2B.41. Table B-1. Summary of Issues Identified in the 2009 MUTCD.