Pavement Markings--Design and Typical Layout Details (2006)

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45 Although Part 3 of the Manual on Uniform Traffic Control Devices contains provisions for pavement markings on streets and highways across the United States, it does not require or recommend uniformity for many of the aspects of pavement marking layout that were studied in this synthesis. This flex- ibility and latitude given to the states and local governments has resulted in a wide variety of policies and practices among the various agencies as documented in this report. Tables 1, 2, and 3 show the range of values and the most common prac- tices found in the design standards for the various agencies for pavement markings at intersections, pavement markings between intersections, and pavement markings at interchanges, respectively. In some cases, such as the width of a line, road users who travel from one state to another might be unaware of the difference. In other cases, road users might experi- ence confusion about pavement markings that are unfamil- iar to them. States and local government agencies most likely appre- ciate some degree of flexibility and latitude as they develop and implement their various pavement marking policies and practices. Variations in line widths and sizes of gaps between line segments in broken or dotted lines may be attributable to the economics of construction and maintenance. States with tight budgets might specify narrower lines and longer gaps to save money, whereas states that have larger proportions of older drivers might favor wider lines and shorter gaps. It is hoped that this synthesis will be used by FHWA and the National Committee on Uniform Traffic Control Devices in the development of the 2008 edition of Part 3 of the Man- ual on Uniform Traffic Control Devices to develop new stan- dards, upgrade existing guidance to standards, and upgrade existing options to guidance. In addition, it is hoped that state and local governmental agencies will use the information in this synthesis to determine the most common policies and practices in each area of interest as they develop or revise their pavement marking design standards. Because this synthesis was limited to a finite number of areas of interest, there remains a need to research and syn- thesize other aspects of pavement marking layouts. Among the pavement markings not included in this synthesis were: • Types and patterns of longitudinal lines, • Use of black contrast markings on concrete surfaces, • Centerline markings on two-lane roads approaching signals and STOP signs, • No-passing zones on two-lane roads approaching inter- sections and grade crossings, • Railroad–highway grade crossings, • Transitions between divided and undivided highways, • Dotted guidelines and lane line extensions through intersections, • Edge line extensions through medians and intersections, • Yield lines and yield ahead symbols, • Markings on acceleration lanes downstream from the gore area, • Markings on deceleration lanes upstream from the gore area, • Exit ramps with through lane drops, • Exit ramps with through lane drop and option lane, • Reversible lanes, • Curb markings, • Parking spaces, • Accessible parking for persons with disabilities, • Bypass lanes, • Passing flare or auxiliary bypass lanes at the top of T intersections, • Paved turnouts, • Bus turnouts, • Truck and bus turnouts at non-exempt railroad cross- ings, • Runaway truck ramps, • Speed measurement markings, • High-occupancy vehicle and other preferential lane markings, • Approaches to narrow bridges, • Bike lanes, • Speed humps and speed tables, • Roundabouts, • Toll plazas, • Rest areas, • Raised pavement markers, • Rumble strips, • Delineators, • Object markers, • Cattle guards, • Temporary traffic control, and • Markings that are presently in the experimental stage. CHAPTER SIX CONCLUSIONS AND FUTURE RESEARCH NEEDS

46 Range Most Common Practice Area of Interest Low End High End Practice No. of Agencies Turn Lanes Type of lane line between a turn bay and the adjacent through lane Broken lane line Solid lane line Solid lane line 42 of 47 Width of lane line between a turn bay and the adjacent through lane 4 in. 12 in. 8 in. 15 of 31 Length of lane line between a turn bay and the adjacent through lane Half the length of the full-width turn lane Entire length of the full-width turn lane Entire length of the full-width turn lane 13 of 26 Type of lane line between a dropped lane and the adjacent through lane Broken lane line Solid lane line Solid lane line 10 of 14 Width of lane line between a dropped lane and the adjacent through lane 4 in. 8 in. 8 in. 3 of 5 Use versus non-use of turn arrows in turn bays Typically not used Required Required 38 of 47 Use versus non-use of only word markings in turn bays Not used Required Optional 12 of 30 Placement of turn arrow nearest to the stop line in turn bays 4 ft upstream 75 ft upstream 20 ft upstream 7 of 38 Placement of word or symbol marking nearest to the upstream end of the full-width turn lane in turn bays 0 ft downstream 33 ft downstream 0 ft downstream 15 of 22 Use versus non-use of turn arrows in dropped lanes Required Required Required 14 of 14 Use versus non-use of only word markings in dropped lanes Optional Required Required 10 of 14 Lane Lines for Dual Turn Lanes Type of lane line between the two lanes of dual turn lanes Broken lane line Solid lane line Solid lane line 8 of 11 Width of lane line between the two lanes of dual turn lanes 4 in. 8 in. 8 in. 3 of 7 Length of lane line between the two lanes of dual turn lanes At least 100 ft Entire length of the full-width turn lanes Entire length of the full-width turn lanes 6 of 7 Type of lane line between dual turn lanes and the adjacent through lane Combination solid and dotted lane line Solid lane line Solid lane line 10 of 11 Width of lane line between dual turn lanes and the adjacent through lane 4 in. 8 in. 8 in. 4 of 7 Length of lane line between dual turn lanes and the adjacent through lane Entire length of the full-width turn lanes Entire length of the full-width turn lanes plus half of taper Entire length of the full-width turn lanes 6 of 7 Lane Line Extensions into Intersection for Dual Turn Lanes Use versus non-use of dotted lines Optional Required Optional 13 of 23 Pattern of dotted lines 0.5-ft segments with 2-ft gaps 3-ft segments with 9-ft gaps 2-ft segments with 4-ft gaps 13 of 26 Width of dotted lines 4 in. 8 in. 4 in. 6 of 7 Use and Type of Dotted Lines in Turn Lane Tapers Use versus non-use of dotted lines Not used Required Not used 30 of 43 Pattern of dotted lines 2-ft segments with 4-ft gaps 6-ft segments with 10-ft gaps 2-ft segments with 4-ft gaps 5 of 12 TABLE 1 SUMMARY OF RANGES AND MOST COMMON PRACTICES IN CHAPTER TWO—PAVEMENT MARKINGS AT INTERSECTIONS

47 Range Most Common Practice Area of Interest Low End High End Practice No. of Agencies Width of dotted lines 4 in. 8 in. 4 in. 3 of 6 Left-Turn Lanes Added Between Through Lanes of Two-Lane Highways Amount of widening Half of left-turn lane width Full width of left- turn lane Full width of left- turn lane 17 of 21 Distance from full shadowing to upstream end of left-turn taper 0 ft Half of shifting taper 0 ft 13 of 17 Length of left-turn taper 50 ft 180 ft No two alike 1 of 21 Solid Lane Lines Between Through Lanes on Signalized Approaches Use versus non-use of solid lane lines between through lanes Broken lane line Solid lane line Broken lane line 29 of 42 Length of solid lane line between through lanes 27 ft 500 ft 50 ft 4 of 13 Width of solid lane line between through lanes 4 in. 6 in. 4 in. 6 of 13 Crosswalks Use of standard and high-visibility crosswalks Standard crosswalks only High-visibility crosswalks only Standard or high- visibility crosswalks may be used 33 of 50 Minimum width of crosswalks 6 ft (measured to outside edges of transverse lines) 20 ft 6 ft (measured to inside edges of transverse lines) 17 of 44 Width of transverse crosswalk lines 6 in. 24 in. 12 in. 12 of 40 Design of high-visibility crosswalks Longitudinal lines only Longitudinal (or diagonal) lines and transverse lines Longitudinal lines only 21 of 38 Width of longitudinal and diagonal lines 12 in. 36 in. 24 in. 17 of 38 Spacing of longitudinal and diagonal lines 12 in. 60 in. 24 in. 14 of 37 Use of standard and high-visibility crosswalks Standard crosswalks only High-visibility crosswalks only Standard or high- visibility crosswalks may be used 33 of 50 Stop Lines Use versus non-use of stop lines Not used if crosswalks are present Required on signalized approaches Required on signalized approaches 42 of 46 Width of stop lines 12 in. 24 in. 24 in. 24 of 43 Placement of stop lines 4 ft At least 5 ft At least 4 ft 21 of 38 Right-Turn Channelizing Islands Width of lines that mark the edges of right- turn channelizing islands 4 in. 48 in. 8 in. 12 of 18 Width of lines within right-turn channelizing islands 6 in. 24 in. 12 in. 8 of 18 Spacing of lines within right-turn channelizing islands 5 ft Number of feet equals posted speed limit in mph Tie between 10 ft and 20 ft 4 of 16 TABLE 1 SUMMARY OF RANGES AND MOST COMMON PRACTICES IN CHAPTER TWO—PAVEMENT MARKINGS AT INTERSECTIONS (Continued )

TABLE 2 SUMMARY OF RANGES AND MOST COMMON PRACTICES IN CHAPTER THREE—PAVEMENT MARKINGS BETWEEN INTERSECTIONS 48 Range Most Common Practice Area of Interest Low End High End Practice No. of Agencies Minimum Length of Passing Zones Minimum length of passing zones 200 ft 1,000 ft 400 ft 10 of 22 Minimum Length of No-Passing Zones Minimum length of no-passing zones 250 ft 550 ft 500 ft 12 of 14 Two-Way Left-Turn Lanes (2WLTLs) Use versus non-use of left-turn arrows Optional Required Required 33 of 37 Spacing between opposing left-turn arrows in a set of arrows 5 ft 33 ft 32 ft 13 of 36 Minimum spacing from one set of arrows to the next set of arrows 100 ft 1,300 ft Tie between 100 ft and 200 ft 2 of 10 Maximum spacing from one set of arrows to the next set of arrows 200 ft 2,640 ft 300 ft 4 of 14 Spacing from one set of arrows to the next set of arrows 200 ft 1,320 ft No two alike 1 of 12 Climbing or Passing Lanes Type of lane line Broken lane line Double broken lane line Broken lane line 19 of 22 Start (upstream end) of lane line (measured from upstream end of full-width climbing or passing lane) 0 ft 250 ft downstream 0 ft 18 of 22 End (downstream end) of lane line (measured from downstream end of full-width climbing or passing lane) 0 ft 650 ft upstream 0.75D (where D is the advance placement distance for a Lane Ends sign) 7 of 18 Use of lane-reduction arrows Not used Required Not used 14 of 18 Number of lane-reduction arrows At least 2 3 3 3 of 4 Passing permitted or prohibited in opposing (single-lane) direction Permitted Prohibited Permitted 17 of 21 Lane Reductions Downstream end of broken lane line (measured from upstream end transition taper) 0 ft 565 ft upstream 0.75D (where D is the advance placement distance for a Lane Ends sign) 11 of 31 Use of lane-reduction arrows Not used Required Not used 17 of 31 Number of lane-reduction arrows 2 5 3 7 of 14 Painted Medians, Paved Shoulders, and Approaches to Obstructions Use versus non-use of diagonal lines within painted medians Not used Used Used 27 of 39 Width of diagonal lines within painted medians 6 in. 24 in. 12 in. 12 of 34 Spacing of diagonal lines within painted medians 5 ft 100 ft 20 ft 5 of 33 Lane lines surrounding painted medians Double yellow centerlines 12-in.-wide solid lines Double yellow centerlines 37 of 39 Use versus non-use of diagonal lines on paved shoulders Not used Optional Optional 18 of 20 Width of diagonal lines on paved shoulders 6 in. 24 in. 12 in. 9 of 20 Spacing of diagonal lines on paved shoulders 5 ft 100 ft 20 ft 2 of 17 Width of diagonal lines or chevrons on approaches to obstructions 8 in. 18 in. 12 in. 6 of 8 Spacing of diagonal lines or chevrons on approaches to obstructions 5 ft 25 ft 5 ft 2 of 6

49 Range Most Common Practice Area of Interest Low End High End Practice No. of Agencies Entrance Ramp Gores Width of channelizing lines 4 in. 12 in. 8 in. 26 of 43 Upstream end of the channelizing line on the left-hand side of the entrance ramp (measured from the upstream end of the paved gore) 0 ft 50 ft 0 ft 25 of 42 Downstream end of the channelizing line on the left-hand side of an entrance ramp with a tapered acceleration lane At upstream end of paved gore At downstream end of paved gore At point where ramp and mainline lane are 6 ft apart 11 of 26 Use versus non-use of a channelizing line on the right-hand side of the mainline roadway Not used Required Required 26 of 42 Upstream end of the channelizing line on the right-hand side of the mainline roadway (measured from the upstream end of the paved gore) 0 ft 50 ft 0 ft 23 of 34 Use versus non-use of chevrons within the paved gore Not used Required Not used 36 of 44 Width of chevrons within the paved gore 8 in. 24 in. 12 in. 2 of 7 Spacing of chevrons within the paved gore 7 ft 100 ft 20 ft 2 of 7 Exit Ramp Gores Width of channelizing lines 6 in. 12 in. 8 in. 27 of 44 Use versus non-use of channelizing line on right-hand side of mainline roadway Required Required Required 44 of 44 Upstream end of channelizing lines for exit ramps with tapered deceleration lanes At point where full width of exit ramp becomes available At point where full width of exit ramp becomes available At point where full width of exit ramp becomes available 44 of 44 Downstream end of channelizing line on left- hand side of exit ramp (measured from the downstream end of the paved gore) 0 ft 50 ft 0 ft 24 of 43 Downstream end of channelizing line on right- hand side of mainline roadway (measured from the downstream end of the paved gore) 0 ft 150 ft 0 ft 21 of 43 Use versus non-use of chevrons or diagonal lines within the paved gore Not used Required Not used 18 of 44 Width of chevrons or diagonal lines within the paved gore 8 in. 24 in. 12 in. 11 of 25 Spacing of chevrons or diagonal lines within the paved gore 7 ft 100 ft 20 ft 5 of 23 Use versus non-use of dotted line in the departure area of a tapered deceleration lane Not used Required Required 20 of 41 Width of dotted line in the departure area of a tapered deceleration lane 4 in. 8 in. 4 in. 15 of 28 Type of dotted line in the departure area of a tapered deceleration lane 2-ft segments with 4-ft gaps 5-ft segments with 20-ft gaps 2-ft segments with 4-ft gaps 12 of 28 TABLE 3 SUMMARY OF RANGES AND MOST COMMON PRACTICES IN CHAPTER FOUR—PAVEMENT MARKINGS AT INTERCHANGES