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

Chapter: Chapter Two - Pavement Markings at Intersections

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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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Suggested Citation:"Chapter Two - Pavement Markings at Intersections." National Academies of Sciences, Engineering, and Medicine. 2006. Pavement Markings--Design and Typical Layout Details. Washington, DC: The National Academies Press. doi: 10.17226/13947.
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5TURN LANES Figure 2 illustrates some of the characteristics of turn lanes and their associated pavement markings. 2003 MUTCD Provisions The MUTCD does not require or recommend a specific type or width of lane line turn lanes and adjacent through lanes. Figures 3B-7, 3B-11, and 3B-22 show a normal solid lane line between the turn lane and the adjacent through lane. Figures 3B-11 and 3B-22 show the upstream end of the solid lane line to be lined up with the upstream end of the full- width turn lane (see Appendix A for figures). Paragraphs 3 and 4 of Section 3B.04 contain the follow- ing standards: “Where crossing the lane line markings with care is permitted, the lane line markings shall consist of a normal [4- to 6-in.-wide] broken white line. Where crossing the lane line markings is discouraged, the lane line markings shall consist of a normal [4- to 6-in.-wide] solid white line.” Paragraphs 5 and 6 of Section 3B.04 contain the following options: “Solid white lane line markings may be used to sep- arate through traffic lanes from auxiliary lanes, such as uphill truck lanes, left- or right-turn lanes, and preferential lanes. They may also be used to separate traffic lanes approaching an intersection. Wide [8- to 12-in.-wide] solid lane line mark- ings may be used for greater emphasis.” For turn lanes where a through lane becomes a mandatory turn lane, the legends in Figures 3B-11 and 3B-22 note that the use of turn arrows is required, and the legend for Figure 3B-22 states that the use of ONLY word markings is optional. For separate left-turn bays, the legends in Figures 3B-7, 3B-11, and 3B-22 note that the use of turn arrows is optional. Paragraph 14 of Section 3B.19 contains the following standard: “Where through traffic lanes approaching an inter- section become mandatory turn lanes, lane-use arrow mark- ings (see Figure 3B-21) shall be used and shall be accompa- nied by standard signs.” Although this standard is universally followed, no standard is given regarding the use of ONLY word markings or the number or placement of turn arrows. Paragraphs 17 and 18 of Section 3B.19 contain the follow- ing options: “Lane-use arrow markings (see Figure 3B-21) may be used to convey either guidance or mandatory messages. The ONLY word marking (see Figure 3B-20) may be used to supplement lane-use arrow markings (see Figure 3B-22).” Paragraph 23 of Section 3B.19 contains the following support: “Lane-use arrow markings are often used to provide guidance in turn bays (see Figure 3B-22), where turns may or may not be mandatory, and in two-way left-turn lanes (see Figure 3B-7).” Paragraph 6 of Section 3B.19 contains the following guid- ance: “Except for the two opposing arrows of a two-way left- turn lane marking (see Figure 3B-7), the longitudinal space between word or symbol message markings, including arrow markings, should be at least four times the height of the char- acters for low-speed roads, but not more than ten times the height of the characters under any conditions.” Because both the left-turn (or right-turn) arrow symbol and the ONLY word marking typically have a height of 6 to 8 ft, this guid- ance essentially states that the space between word or sym- bol message markings should be no less than 24 to 32 ft and no more than 60 to 80 ft. Type of Lane Line Between a Turn Bay and Adjacent Through Lane (47 agencies) Except for the five agencies cited here, the design standards consistently show only a solid lane line between a turn bay and the adjacent through lane. The design standards for South Carolina show a broken lane line (10-ft segments with 30-ft gaps) being used between the turn lane and the adjacent through lane. The design standards for Maryland state that the solid lane line between the turn lanes and the adjacent through lane starts at the stop line and ends at the halfway point of the full- width turn lanes. A dotted line (3-ft segments with 9-ft gaps) may be used from the halfway point to the upstream end of the full-width turn lanes. The design standards for New Hampshire show a broken lane line (10-ft segments with 30-ft gaps) being used up- stream of the upstream end of the solid lane line between the turn lane and the adjacent through lane, even for turn bays. The length of the broken lane line is based on the posted speed limit. CHAPTER TWO PAVEMENT MARKINGS AT INTERSECTIONS

The design standards for North Carolina show that if the length of the full-width turn lane is more than 250 ft, the solid lane line starts at the stop line and ends 250 ft upstream from the stop line. A 4- or 6-in.-wide dotted line (2-ft segments with 13-ft gaps) starts at the upstream end of the solid lane line and ends at the upstream end of the left-turn lane taper. The design standards for West Virginia show that a solid lane line with a maximum length of 200 ft is used between the turn lane and the adjacent through lane. A broken lane line (10-ft segments with 30-ft gaps) is used between the turn lane and the adjacent through lane upstream of the solid lane line for the remainderof a full-width turn lane that is longer than 200 ft. Width of Lane Line Between a Turn Bay and Adjacent Through Lane (31 agencies) The following widths are explicitly specified in the design standards for the lane line between a turn bay and the adja- cent through lane: AR, DE, IN, ME, MI, NE, SD, TN, VT—4 in. NC, PA—4 or 6 in. FL, KS—6 in. WV—6 to 8 in. AL—6 or 8 in. AK, CA, CO, ID, LA, MT, NV, ND, OH, OR, TX, UT, WI, WY, DC—8 in. AZ—12 in. Length of Lane Line Between a Turn Bay and Adjacent Through Lane (26 agencies) The following points (measured downstream from the up- stream end of the full-width turn lane) are explicitly specified in the design standards for the upstream end of the solid lane line between a turn bay and the adjacent through lane (L is the length of the full-width turn lane): LA—0.5L MD—0.5L (an optional dotted line comprised of 3-ft seg- ments with 9-ft gaps may be used from the upstream end of the lane line to the upstream end of the full-width turn lane) 6 WY (right-turn lanes)—0.5L (an optional dotted line comprised of 2-ft segments with 6-ft gaps may be used from the upstream end of the lane line to the upstream end of the right-turn taper) DE, NV, PA—0.33L MN, WA—50 ft FL—20 to 120 ft (based on speeds ranging from 35 to 65 mph) MT—20 ft ID—10 ft MI—0 ft for left-turn lanes and 25 ft for right-turn lanes NC—0 ft for turn lanes that are 250 ft or less in length (for turn lanes longer than 250 ft, the solid lane line ends 250 ft upstream from the stop line) AK, AZ, NE, OK, SD, TN, VT, VA, WI, WY (left-turn lanes), PR, LAN, TUC—0 ft. The design standards for Utah state that the solid lane line starts at the stop line and ends at least 100 ft upstream from the stop line. Other Considerations Regarding Lane Lines for Turn Bays (1 agency) The design standards for Idaho (see Figure 3) show that the centerline on the left-hand side of a turn bay extends beyond the stop line and terminates at the nearest crosswalk line. The last 30 ft of the centerline (including the portion beyond the stop line) is a solid yellow median that is 2 to 4 ft wide (if space is limited, the solid yellow median can be as narrow as 8 in. wide). The double yellow centerline separates into a pair of double yellow centerlines that taper away from each other to connect to the edges of the solid yellow median. Type of Lane Line Between a Dropped Lane and Adjacent Through Lane (14 agencies) Except for the four agencies listed here, the design standards consistently show a solid lane line between a dropped lane and the adjacent through lane. The design standards for California note that an 8-in.- wide solid line preceded by an 8-in.-wide dotted line may be placed in advance of an intersection where the outside lane is dropped as a mandatory turn lane. The dotted line starts Turn lane taper Separate turn bay Upstream end of full-width turn lane ONLY word marking Turn arrow Lane lines Dropped lane Dotted line in turn lane taper Adjacent through lane FIGURE 2 Characteristics of turn lanes.

7where a special RIGHT LANE TURNS RIGHT AHEAD yellow, diamond-shaped warning sign is placed at a distance D upstream from the upstream end of the 8-in. solid line. (The distance D is the advance placement distance in feet for warning signs per the MUTCD.) The design standards for Maryland state that the normal broken lane line shall become a dotted line (3-ft segments with 9-ft gaps) beginning at the farthest upstream turn arrow, and shall become a solid lane line at the halfway point between the farthest upstream turn arrow and the stop line. The design standards for Oregon show an 8-in.-wide solid line preceded by an 8-in.-wide dotted line (3-ft segments sep- arated by 9-ft gaps) being placed in advance of an intersection where the outside lane is dropped as a mandatory turn lane. The design standards for South Carolina show a broken lane line (10-ft segments with 30-ft gaps) being used between a dropped lane and the adjacent through lane. Width of Lane Line Between a Dropped Lane and Adjacent Through Lane (5 agencies) The following widths are explicitly specified in the design standards for the solid lane line between a dropped lane and the adjacent through lane: NC—4 to 6 in. KS—6 in. AR, CA, FL—8 in. Length of Lane Line Between a Dropped Lane and Adjacent Through Lane (2 agencies) The following lengths are explicitly specified in the design standards for the solid lane line between a dropped lane and the adjacent through lane: NC—200 ft KS—561 ft. Use Versus Non-Use of Turn Arrows in Turn Bays (47 agencies) Except for the nine agencies listed here, the design standards consistently indicate that the use of turn arrows in turn bays is recommended or required. The design standards for Tennessee state that turn arrows are typically used in turn bays. The design standards for five agencies (IA, MD, PA, UT, and WY) state that the use of turn arrows in turn bays is optional. The design standards for Delaware state that the use of turn arrows in right-turn bays is optional. The design standards for Colorado show turn bays without turn arrows. However, the design standards also show a curved extension of the lane line partially into the intersection to com- municate to drivers when they arrive at the downstream end of the turn bay that they must turn either left or right. 500' (150m) max. recommended spacing 30'(9.0 m) R3-10A Mount R3-9 sign overhead and over the two-way turn lane, whenever possible. Use post-mounted R3-10A as an alternate or supplement to R3-9. Private Approach or Minor Street PrivateApproach Minor Street 8'-3" (2.5 m) L/2 25'(7.6 m)L/2 50' (15 m) min.18' - 32' (5 - 10 m) desirable to the nearest approach or minor street Major Street 2' - 4' (600 mm -1.2 m) median solid yellow 8" (200 mm) solid white Variable 10' (3 m) Desirable gap length X = S (speed mph) x 10 2 [X = S (speed km/h)] NOTES: 1. Pavement Markings in the through lanes are optional and should be installed only if justified. 2. Two-way left turn lanes should be continuous through "T" intersections, but may be broken for 4-way intersections. 3. Elimination of double yellow reverse curve may be used at the end of two-way left turn lanes at high volume signalized intersections. 4. See Standard Drwg. I-21 for pavement marking details. 14' and 16' (4.2 and 4.8 m) median width R3-9 FIGURE 3 Solid yellow median used by Idaho DOT (Source: 2003 Idaho DOT traffic manual).

The design standards for South Carolina note that turn arrows are typically not used in turn bays. Use Versus Non-Use of ONLY Word Markings in Turn Bays (30 agencies) The design standards for 11 agencies (AK, AZ, AR, MT, NV, NY, ND, VT, WI, DC, and PR) state or show that the use of ONLY word markings in turn bays is required. The design standards for Tucson/Pima County, Arizona, show that the use of ONLY word markings in turn bays is required for long turn lanes. The design standards for 12 agencies (AL, ID, IA, ME, MA, OH, OK, OR, PA, UT, WV, and WY) indicate that the use of ONLY word markings in turn bays is optional. The design standards for six agencies (GA, MD, RI, SC, CLT, and LAN) note that ONLY word markings are not used in turn bays. Placement of Turn Arrow Nearest to Stop Line in Turn Bays (38 agencies) The following distances are explicitly specified in the design standards for the distance from the upstream edge of the stop line to the top of the turn arrow nearest to the stop line: AK, VT—4 ft NV—8 ft OH—at least 10 ft from the downstream edge of the stop line in urban areas and at least 30 ft from the down- stream edge of the stop line in rural areas SD—17 ft ME—20 ft (shown as 6 m) from the downstream edge of the stop line MA—20 ft (shown as 6 m) AZ, IN, WI, WY, TUC—20 ft MT, PA—at least 20 ft OK—20 ft for turn lanes shorter than 150 ft and 30 ft for longer turn lanes NY—21 ft (shown as 6.5 m) GA, ID, CLT—25 ft MI, KS—at least 25 ft AL—30 ft MN—30 to 80 ft for turn lanes longer than 200 ft, and at the midpoint of the full-width turn lane for turn lanes of 200 ft or less in length TX—typically 32 ft KY—32 to 80 ft TN, WA—50 ft NC—50 ft for long turn lanes MO—75 ft. The following distances are explicitly specified in the design standards for the distance from the upstream edge of 8 the stop line to the tip of the arrowhead for the turn arrow nearest to the stop line: OR—10 ft FL, IA—25 ft. The following distances are explicitly specified in the design standards for the distance from the upstream edge of the stop line to the center of the turn arrow nearest to the stop line: UT—20 ft MD—50 ft. The following distances are explicitly specified in the design standards for the distance from the upstream edge of the stop line to the bottom of the turn arrow nearest to the stop line: NH—40 ft LA, VA, WV—50 ft. Placement of Word or Symbol Marking Nearest to Upstream End of Full-Width Turn Lane in Turn Bays (22 agencies) The following points (measured downstream from the up- stream end of the solid lane line between the turn bay and the adjacent through lane) are explicitly specified in the design standards for the bottom (unless otherwise stated) of the word or symbol marking nearest to the upstream end of the full-width turn lane: CA—near the point of entrance WA—0 ft (measured to center of arrow) AL, AK, AZ, DE, ID, KS, SD, VT, VA, PR, LAN, TUC—0 ft MI, NC—0 ft for long turn lanes WI—0 or 20 ft depending on the turn lane length OR—10 ft (measured to tip of arrowhead) FL—15 ft MN—20 ft for long turn lanes TN—25 ft NY—33 ft (shown as 10 m) for long turn lanes. Placement of Other Turn Arrows and ONLY Word Markings in Turn Bays (32 agencies) The term “space between” in this section refers to the un- marked space between the bottom of a word or symbol mark- ing and the top of the next upstream word or symbol mark- ing. The term “interval between” in this section refers to the distance between the top (or center or bottom) of a word or symbol marking and the top (or center or bottom) of the next word or symbol marking. The following distances are explicitly specified in the design standards for the space between ONLY word markings and the next downstream turn arrow:

9VT—4 ft AK—4 ft for the turn arrow nearest to the stop line and 35 to 80 ft for turn arrows farther upstream based on the speed NY—5 ft OR—30 ft AL, TX, WI, WY—32 ft MA—32 ft (shown as 9.8 m) MI—32 ft for 25 mph or less, 48 ft for 30 or 35 mph, 64 ft for 40 or 45 mph, and 80 ft for 50 mph or more PR—33 ft ND—typically 44 ft, but no less than 32 ft IN, PA—four times the character height for low-speed roadways and ten times the character height for high- speed roadways. The following distances are explicitly specified in the design standards for the interval between ONLY word mark- ings and the next downstream turn arrow: FL—15 ft LA—25 ft UT—30 ft OK—35 ft for turn lanes shorter than 150 ft and 35 and 55 ft for longer turn lanes ID, WV—midway between the upstream and downstream turn arrows. The following minimum spaces between subsequent word or symbol markings are explicitly specified in the design standards: OH—24 ft in urban areas and 32 ft in rural areas AZ, KY, NV—32 ft AL—100 ft. The following typical spaces between subsequent word or symbol markings are explicitly specified in the design stan- dards: IL—20 ft in urban areas and 50 ft in rural areas WY, DC—32 ft ME—53 ft (shown as 16 m) between turn arrows if ONLY word markings are not used; 33 ft (shown as 10 m) between turn arrows and ONLY word markings if ONLY word markings are used CLT—50 ft between Turn Arrows 1 and 2 and 3 (where Turn Arrow 1 is the turn arrow nearest to the stop line), and 100 ft between Turn Arrows 3 and 4 and 5 and 6, and 150 ft for any additional upstream turn arrows WV—72 ft for speeds of 40 mph or less and 168 ft for speeds higher than 40 mph KS—no less than four times the character height or more than ten times the character height. The following typical intervals between subsequent word or symbol markings are explicitly specified in the design standards: UT—30 ft IA—75 ft between turn arrows (if ONLY word markings are used they are centered in the 75-ft distance between the subsequent arrows) GA—100 ft (because all turn lanes are required to have at least two turn arrows, a shorter spacing may be used for the second arrow in a short turn lane) WA—100 ft LA—125 ft between turn arrows. The following maximum spaces between subsequent word or symbol markings are explicitly specified in the design standards: OH—60 ft in urban areas and 80 ft in rural areas AZ, KY, NV—80 ft AL—200 ft. Other Considerations Regarding Arrows and Word Markings in Turn Bays (25 agencies) The design standards for Arizona state that an ONLY word marking is to be installed midway between the turn arrow nearest the stop line and the turn arrow nearest to the up- stream end of the lane line. The turn arrow nearest to the upstream end of the lane line is always required, but the turn arrow nearest to the stop line may be omitted when the length of the turn lane is 150 ft or less. The design standards for Arkansas show that a 12-in.-wide stop line is used at the end of major street left-turn lanes even if no signals or STOP signs are controlling the approach. The design standards for California note that an 8-ft-long turn arrow is typically used, but that high approach speeds may justify the use of a 24-ft-long turn arrow. The design standards for Florida state that for turn lanes where the length of the solid lane line is less than 100 ft, only one turn arrow is used. Two turn arrows are used for turn lanes where the length of the solid lane line is 100 to 150 ft. Three turn arrows are used for turn lanes where the length of the solid lane line is 150 to 200 ft. For turn lanes where the length of the solid lane line is more than 200 ft, an additional turn arrow is added for each additional 100 ft. If more than two turn arrows are used, they are spaced evenly between the first and last turn arrows. ONLY word markings are used in conjunction with lane use arrows where a movement that would otherwise be legal is to be prohibited. The design standards for Maryland require that for dual turn lanes, turn arrows shall be placed in each lane at the halfway point of the full-width turn lanes. A second set of turn arrows may be placed in each lane halfway between the required arrows and the upstream end of the full-width turn lanes (three-quarters of the distance from the stop line to the upstream end of the full-width turn lanes).

The design standards for Michigan provide a second option for marking turn lanes that consists entirely of word markings. The top of the letters of an ONLY word marking is placed at least 25 ft from the stop line. The top of the let- ters of a TURN message is placed upstream a distance D from the bottom of the letters of the ONLY word marking, and the top of the letters of a LEFT message is placed upstream a distance D from the bottom of the letters of the TURN message. The distance D is based on the posted speed limit as follows: 32 ft for 25 mph or less, 48 ft for 30 or 35 mph, 64 ft for 40 or 45 mph, and 80 ft for 50 mph or more. The design standards for Missouri state that two turn arrows are used for the first 200 ft of the turn lane and one additional turn arrow is placed for every additional 400 ft of the turn lane. The design standards for Montana state that a second turn arrow and ONLY word marking are used if the average annual daily traffic exceeds 5,000 or if the length of the turn lane is more than 150 ft. The distance between turn arrows and ONLY word markings in the turn lane is not specified, but it is clear that each ONLY word marking appears just before the bottom of the turn arrow so that they function as a single message. The spacing between successive sets of turn arrows and ONLY word markings varies with the design speed, and it is suggested that a spacing of approximately four times the character height be used on low-speed facili- ties (45 mph or less) and up to ten times the character height be used on high-speed facilities (50 mph or more). The design standards for Nevada note that if the length of the solid lane line is less than 55 ft, a single turn arrow is used and is placed such that the top of the turn arrow is 8 ft from the stop line. If the length of the solid lane line is 55 to 95 ft, an ONLY word marking and a turn arrow are used, with the top of the letters of the ONLY word marking placed 8 ft from the stop line, and the bottom of the turn arrow lined up with the end of the lane line (this is reverse reading with drivers encountering the turn arrow first and the ONLY word mark- ing second). If the length of the solid lane line is more than 95 ft, an alternating series of turn arrows and ONLY word markings are used, with the top of the turn arrow nearest to the stop line placed 8 ft from the stop line and with the spac- ing between the bottom of subsequent turn arrows or ONLY word markings being 32 to 80 ft from the top of the next turn arrow or ONLY word marking. The design standards for New Hampshire provide specific layouts of turn arrows and ONLY word markings for the fol- lowing lengths of solid lane lines between the turn lane and the adjacent through lane: 100, 150, 200, 250, 300, and 350 ft. For a 100-ft lane line, an ONLY word marking and a turn arrow are used, with the bottom of the letters of the ONLY word marking placed 40 ft from the stop line, and the bottom of the turn arrow lined up with the upstream end of the lane line (this is reverse reading, with drivers encountering the turn arrow first and the ONLY word marking second). For 10 150- and 200-ft lane lines, a turn arrow is placed such that the bottom of the arrow is 40 ft from the stop line, a second turn arrow is placed such that the bottom of the arrow is lined up with the upstream end of the lane line, and an ONLY word marking is placed halfway between the two turn arrows. For 250-, 300-, and 350-ft lane lines, a turn arrow is placed such that the bottom of the arrow is 40 ft from the stop line, a sec- ond turn arrow is placed such that the bottom of the arrow is lined up with the upstream end of the lane line, a third turn arrow is placed halfway between the other two turn arrows, and two ONLY word markings are placed at the halfway points between the three turn arrows. The design standards for New York note that if the length of the full-width turn lane is less than 90 ft, only one turn arrow and ONLY word marking is provided. If the length of the full-width turn lane is between 90 and 135 ft, a second turn arrow and ONLY word marking is provided, with the distance between the top of the second turn arrow 25 to 65 ft (shown as 7.5 to 20 m) from the bottom of the letters of the first ONLY word marking. If the length of the full-width turn lane is between 135 and 250 ft, a second turn arrow and ONLY word marking is provided with the distance between the top of the second turn arrow 65 ft (shown as 20 m) from the bottom of the letters of the first ONLY word marking. If the length of the full-width turn lane is between 250 and 500 ft, a second turn arrow and ONLY word marking is pro- vided, with the distance between the top of the second turn arrow 65 ft (shown as 20 m) from the bottom of the letters of the first ONLY word marking, and a third turn arrow and ONLY word marking is provided, with the bottom of the ONLY word marking being 33 ft (shown as 10 m) down- stream from the start of the full-width turn lane. The design standards for North Carolina state that if the length of the full-width turn lane is less than 125 ft, a single turn arrow is placed halfway between the stop line and the end of the full-width turn lane. If the length of the full-width turn lane is more than 125 ft but less than 250 ft, two turn arrows are placed in the lane with the top of the turn arrow nearest to the stop line placed 50 ft from the stop line and the other turn arrow placed such that the bottom of the arrow is lined up with the upstream end of the full-width turn lane. If the length of the full-width turn lane is more than 250 ft, three turn arrows are placed in the lane with the top of the turn arrow nearest to the stop line placed 50 ft from the stop line, a second turn arrow placed such that the bottom of the arrow is lined up with the upstream end of the full-width turn lane, and a third turn arrow is centered between the other two. Additional arrows may be used if the turn lane is long. The design standards for Oklahoma state that if the length of the turn lane is less than 100 ft, only one turn arrow is used with the top placed 20 ft from the stop line, and an optional ONLY word marking may be provided with the top of the let- ters 35 ft upstream from the top of the turn arrow. If the length of the full-width turn lane is 100 to 149 ft, a second

11 turn arrow is provided with the top of the turn arrow 35 ft upstream from the top of the letters of the ONLY word mark- ing. If the length of the full-width turn lane is 150 to 200 ft, the top of the turn arrow that is nearest the stop line is placed 30 ft from the stop line, an optional ONLY word marking may be provided with the top of the letters 55 ft upstream from the top of the turn arrow, and a second turn arrow is pro- vided with the top of the turn arrow 35 ft upstream from the top of the letters of the ONLY word marking. No informa- tion is given for turn lanes that are longer than 200 ft. The design standards for Oregon state that the tip of the arrowhead for the required turn arrow in a turn lane is 10 ft downstream from the upstream end of the full-width turn lane. A second turn arrow may be used and is placed such that the tip of the arrowhead is 10 ft from the stop line. If an optional ONLY word marking is used, then the second turn arrow 10 ft from the stop line is required. The design standards for Tennessee note that if the length of the turn lane is less than 150 ft, only one turn arrow is used, with the top placed 50 ft from the stop line. If the length of the full-width turn lane is 150 to 200 ft, a second turn arrow is provided with the bottom of the turn arrow 25 ft down- stream from the upstream end of the full-width turn lane. If the length of the full-width turn lane is more than 200 ft, additional turn arrows may be equally spaced between the two required turn arrows. The design standards for Texas note that two sets of turn arrows and ONLY word markings are used in turn lanes that are 180 ft or more in length. The top of the turn arrow near- est to the stop line is typically 32 ft from the stop line. The top of the letters of the ONLY word marking is placed 32 ft upstream from the bottom of the turn arrow nearest the stop line. A second turn arrow and a second ONLY word mark- ing are placed 32 ft apart at an unspecified distance upstream in the turn lane. The design standards for Utah and West Virginia require that both turn arrows and ONLY word markings are used where a movement that would otherwise be legal is to be prohibited. The design standards for Vermont state that if the length of the turn lane is less than 100 ft, only one turn arrow and ONLY word marking is provided with the bottom of the let- ters of the ONLY word marking lined up with the upstream end of the full-width turn lane and the turn arrow placed such that the bottom of the arrow is 4 ft downstream from the top of the letters of the ONLY word marking. If the length of the full-width turn lane is 100 to 200 ft, a second turn arrow and ONLY word marking is provided with the top of the turn arrow placed 4 ft from the stop line and the ONLY word marking placed such that the top of the letters of the ONLY word marking is 4 ft upstream from the bottom of the arrow. If the length of the full-width turn lane is more than 200 ft, additional sets of turn arrows and ONLY word markings are provided. At unsignalized, non-stopping approaches, the solid lane line between the turn lane and the adjacent through lane is extended and curved into the intersection until the first conflict point is reached. The design standards for Virginia note that if the length of the turn lane is 300 ft or less, two turn arrows are provided with the bottom of the turn arrow nearest to the stop line located 50 ft from the stop line and the bottom of the other turn arrow lined up with the upstream end of the full-width turn lane. If the length of the full-width turn lane is more than 300 ft, a third turn arrow is placed at the midpoint of the full- width turn lane. The design standards for Wisconsin state that if the length of the turn lane is less than 108 ft, only one turn arrow and ONLY word marking is provided, with the bottom of the let- ters of the ONLY word marking typically 20 ft downstream from the upstream end of the full-width turn lane and the turn arrow typically placed such that the top of the turn arrow is 20 ft from the stop line. If the length of the turn lane is 108 to 167 ft, two turn arrows and an ONLY word marking are pro- vided with the top of the turn arrow nearest to the stop line typically placed 20 ft from the stop line, another turn arrow is placed such that the bottom of the arrow is lined up with the upstream end of the full-width turn lane, and the ONLY word marking placed halfway between the turn arrows. If the length of the turn lane is more than 167 ft, two sets of turn arrows and ONLY word markings are provided (with the bottoms of the turn arrows located 32 ft upstream from the top of the let- ters of the ONLY word marking), with the bottom of the let- ters of an ONLY word marking placed 20 ft downstream from the upstream end of the full-width turn lane and the turn arrow nearest to the stop line typically placed such that the top of the arrow is 20 ft from the stop line. The design standards for the District of Columbia state that markings in turn lanes start with a turn arrow, followed by an ONLY word marking, and ending with an arrow near the stop line, all of which fits within the 90-ft distance of the solid lane line between the through lanes. In longer turn lanes, the markings start with a turn arrow, followed by an ONLY word marking, followed by another turn arrow, fol- lowed by another ONLY word marking, and ending with an arrow near the stop line. The design standards for Puerto Rico note that two sets of turn arrows and SOLO messages are provided in the turn lane. The top of the turn arrow nearest to the stop line is placed an unspecified distance from the stop line. The second set is placed such that the bottom of the SOLO message is lined up with the upstream end of the full-width turn lane. The design standards for the city of Los Angeles state that typically only one turn arrow is used and it is installed such that the bottom of the turn arrow is lined up with the upstream

end of the full-width turn lane. If the turn lane is longer than 250 ft, a second turn arrow is placed at the midpoint of the full-width turn lane. A turn arrow is only placed near the stop line if required by the California DOT (Caltrans) on freeway ramps and other state highway intersections. The design standards for Tucson/Pima County, Arizona, note that at least two turn arrows are placed in turn lanes. The top of the turn arrow nearest to the stop line is typically placed 20 ft from the stop line. The bottom of the other turn arrow is lined up with the upstream end of the full-width turn lane. If the turn lane is 108 to 200 ft in length, an ONLY word mark- ing is placed halfway between the two turn arrows. If the turn lane is more than 200 ft in length, an ONLY word marking and a third turn arrow are placed at one-third points between the two turn arrows, with the ONLY word marking placed closer to the stop line than the third turn arrow. Use Versus Non-Use of Turn Arrows in Dropped Lanes (14 agencies) The design standards consistently are that the use of turn arrows in dropped lanes is required, as stated in Paragraph 14 of Section 3B.19 of the MUTCD. Use Versus Non-Use of ONLY Word Markings in Dropped Lanes (14 agencies) The design standards for 10 agencies (FL, GA, IA, KS, MD, NC, SC, TN, WY, and CLT) state that the use of ONLY word markings in dropped lanes is required. The design standards for Idaho and Rhode Island note that the use of ONLY word markings in dropped lanes is recommended. The design standards for two agencies (Pennsylvania and Oregon) note that the use of ONLY word markings in dropped lanes is optional. Placement of Turn Arrows and ONLY Word Markings in Dropped Lanes (9 agencies) The design standards for Georgia state that the top of each ONLY word marking is separated from the top of the next downstream turn arrow by 100 ft and from the top of the next upstream turn arrow by 50 ft. The design standards for Kansas note that the tip of the arrowhead for the turn arrow nearest to the stop line is at least 25 ft from the stop line. Spacing of alternating turn arrows and ONLY word markings (measured as the blank space between the bottom of one arrow or message to the top of the next arrow or message) is 80 ft. The turn arrow nearest to the upstream end of the lane line is positioned such that the bot- tom of the arrow is lined up with the start of the lane line. 12 The design standards for Maryland state that the minimum configuration of turn arrows and ONLY word markings shall be an arrow-ONLY-arrow sequence, with an equal distance of 40 to 90 ft between the center of the ONLY word marking and the center in each direction of the next turn arrows. The center of the turn arrow nearest to the stop line should be approxi- mately 50 ft from the stop line. Section 3B.19 of the Maryland supplement to the MUTCD has a chart that specifies (based on a variety of speeds) how to add more turn arrows and ONLY word markings to the lane being dropped such that the first turn arrow encountered ranges from 375 ft from the stop line for a prevailing (not posted) speed of 25 mph to 800 ft from the stop line for a prevailing speed of 55 mph. The design standards for North Carolina state that two sets of pavement markings (with each set comprised of two turn arrows and one ONLY word marking) are used in all dropped lanes. In each set, the ONLY word marking is placed halfway between the two turn arrows whose tops are placed 150 ft apart. In the first set, the top of the turn arrow nearest to the stop line is placed 50 ft from the stop line. In the second set, the top of the turn arrow nearest to the stop line is placed 350 ft from the stop line if the speed limit is 35 mph or less, 400 ft from the stop line if the speed limit is 40 to 50 mph, or 650 ft from the stop line if the speed limit is 55 mph or more. The design standards for Oregon specify that two turn arrows are required. The design standards for South Carolina state that two turn arrows, each accompanied by an ONLY word marking, are required. The design standards for Wyoming note that two turn arrows and an ONLY word marking are required. The design standards for the city of Charlotte specify that if the speed limit is 35 mph, a sequence of four turn arrows and two ONLY word markings is used in the downstream direc- tion as follows: a turn arrow, an ONLY word marking, two turn arrows, another ONLY word marking, and a turn arrow. The top of the turn arrow nearest to the stop line is placed 25 ft from the stop line. The next two markings are placed such that the top of the turn arrow or ONLY word marking is 50 ft from the bottom of the next downstream marking. The next three markings are placed such that the top of the turn arrow or ONLY word marking is 100 ft from the bottom of the next downstream marking. If the speed limit is 40 mph or more, the same markings as for a 35 mph speed limit are used, except that an additional turn arrow is placed upstream from the other six markings such that the top of the additional turn arrow is 150 ft from the bottom of the next downstream turn arrow. The design standards for the city of Tucson/Pima County show that lane-reduction arrows and warning signs are used to move through traffic out of the dropped lane before the turn lane markings are started.

13 Design of Turn Arrow Symbols (38 agencies) Drawing “b” in Figure 3B-21 in the 2003 MUTCD shows a design for a Turn Lane-Use Arrow that is 8 ft long. This same 8-ft-long and 6-ft 4-in.-wide turn arrow design is shown in greater detail on Page 10-10 of the 2004 Standard Highway Signs Book. The pattern for an optional narrow elongated turn arrow is shown on Page 10-11 of the 2004 Standard Highway Signs Book; however, exact dimensions are not provided. The design standards for 36 agencies consistently show turn arrow symbol designs that are similar to the 8-ft-long turn arrow shown in Figure 3B-21 in the 2003 MUTCD and on Page 10-10 of the 2004 Standard Highway Signs Book. The design standards for 5 of these 36 agencies (CA, HI, OH, OR, and NYC) also show that narrow elongated lane use arrows that are similar to the turn arrow shown on Page 10- 11 of the Standard Highway Signs Book are available for use. The design standards for one of these 36 agencies (IL) show that a shorter, 6-ft-long turn arrow that is similar to the shape of the turn arrow shown in Figure 3B-21 of the 2003 MUTCD is used in urban areas. The design standards for two agencies (PA and WA) show that the 8-ft-long turn arrow that is similar to the turn arrow shown in Figure 3B-21 of the 2003 MUTCD is not used. An elongated 12-ft-long turn arrow that is similar to the turn arrow shown on Page 10-11 of the Standard Highway Signs Book is the only style of turn arrow that is available for use. LANE LINES FOR DUAL TURN LANES Figure 4 illustrates some of the characteristics of dual turn lanes and their associated pavement markings (see Appendix A for figures). 2003 MUTCD Provisions The MUTCD does not require or recommend a specific type or width of lane line for use with dual turn lanes. Both of the figures in Part 3 (Figures 3B-11 and 3B-22) that show dual turn lanes at an intersection show a normal solid lane line between the two turn lanes. Paragraphs 3 and 4 of Section 3B.04 contain the follow- ing standards: “Where crossing the lane line markings with care is permitted, the lane line markings shall consist of a normal [4- to 6-in.-wide] broken white line. Where crossing the lane line markings is discouraged, the lane line markings shall consist of a normal [4- to 6-in.-wide] solid white line.” Paragraphs 5 and 6 of Section 3B.04 contain the follow- ing options: “Solid white lane line markings may be used to separate through traffic lanes from auxiliary lanes, such as uphill truck lanes, left- or right-turn lanes, and preferential lanes. They may also be used to separate traffic lanes approach- ing an intersection. Wide [8- to 12-in.-wide] solid lane line markings may be used for greater emphasis.” Type of Lane Line Between the Two Lanes of Dual Turn Lanes (11 agencies) Except for the three agencies listed here, the design standards consistently show a solid lane line between the two turn lanes. The design standards for Maryland and Washington State require that the lane line between the two turn lanes is a bro- ken line (10-ft segments with 30-ft gaps) that starts at the stop line and ends at the upstream end of the full-width turn lanes. The design standards for North Carolina require that the solid lane line starts at the stop line and ends at the midpoint of the full-width turn lanes. From the midpoint to the up- stream end of the full-width turn lanes, a broken lane line (10-ft segments with 30-ft gaps) is used. Width of Lane Line Between the Two Lanes of Dual Turn Lanes (7 agencies) The following widths are explicitly specified in the design stan- dards for the lane line between the two lanes of dual turn lanes: MI, TN—4 in. NC—4 or 6 in. FL—6 in. CO, NV, TUC—8 in. Length of Lane Line Between the Two Lanes of Dual Turn Lanes (7 agencies) The following lengths are explicitly specified in the design standards for the lane line between the two lanes of dual turn lanes: CA—at least 100 ft MD, MI, NV, TN, LAN, TUC—entire length of full-width turn lanes. Lane line between two lanes of dual turn lanes Lane line between dual turn lanes and adjacent through lane Solid line between through lanes on a signalized approach Lane line extension into intersection FIGURE 4 Characteristics of dual turn lanes.

Type of Lane Line Between Dual Turn Lanes and Adjacent Through Lane (11 agencies) Except for one agency, the design standards consistently show a solid lane line between the dual turn lanes and the adjacent through lane. The design standards for Maryland state that the solid lane line between the turn lanes and the adjacent through lane starts at the stop line and ends at the halfway point of the full- width turn lanes. A dotted line (3-ft segments with 9-ft gaps) is used from the halfway point to the upstream end of the full- width turn lanes. Width of Lane Line Between Dual Turn Lanes and Adjacent Through Lane (7 agencies) The following widths are explicitly specified in the design standards for the lane line between dual turn lanes and the adjacent through lane: MI, TN—4 in. NC—4 or 6 in. CO, FL, NV, TUC—8 in. Length of Lane Line Between Dual Turn Lanes and Adjacent Through Lane (7 agencies) The following lengths are explicitly specified in the design standards for the lane line between dual turn lanes and the adjacent through lane: 14 MD, MI, NV, NC, TN, TUC—entire length of full-width turn lanes LAN—from the stop line to the midpoint between the upstream end of the full-width turn lanes and the upstream end of the turn lane taper. LANE LINE EXTENSIONS INTO INTERSECTION FOR DUAL TURN LANES Figure 5 shows an example of a lane line extension into an intersection for dual turn lanes. 2003 MUTCD Provisions The MUTCD recommends that dotted or solid line markings be used to extend the lane line between dual turn lanes through an intersection. Figure 3B-11 shows a solid line being used to extend the lane line between dual turn lanes through the intersection. Figure 3B-22 shows a white dotted line being used to extend the lane line between dual turn lanes through the intersection and a single yellow dotted line being used to extend the double yellow centerline to the left of dual left-turn lanes through the intersection. The notes in both of these figures mention that the lane line extensions may be dotted or solid lines (see Appendix A for figures). Item E in Paragraph 1 of Section 3A.05 contains the fol- lowing standards: “A dotted line shall consist of noticeably shorter line segments separated by shorter gaps than used for a broken line. The width of a dotted line shall be at least the (a) Widening on one side only Point where full shadowing first becomes available (b) Symmetrical widening on both sides Shifting taper Shifting taper Left-turn taper Left-turn taper Point where full shadowing first becomes available FIGURE 5 Examples of left-turn lanes added between through lanes of two-lane highways.

15 same as the width of the line it extends.” Even though these provisions are classified as requirements, they do not specify the width or the pattern of dotted lines, which varies signifi- cantly among the policies of the various agencies. Paragraph 3 of Section 3A.05 contains the following option: “A dotted line for line extensions may consist of 2 ft line segments and 2 ft to 6 ft gaps.” Paragraphs 1 and 2 of Section 3B.08 contain the follow- ing standard and option: “Pavement markings extended into or continued through an intersection or interchange area shall be the same color and at least the same width as the line markings they extend, except that a normal line may be used to extend a wide line through an intersection.” This standard specifies the color, but does not specify the use or pattern of pavement marking extensions and gives flexibility as to the width. Paragraphs 3 and 5 of Section 3B.08 contain the follow- ing guidance: “Where highway design or reduced visibility conditions make it desirable to provide control or to guide vehicles through an intersection or interchange, such as at offset, skewed, complex, or multilegged intersections, on curved roadways, or where multiple turn lanes are used, dot- ted line markings should be used to extend longitudinal line markings through an intersection or interchange area. Where greater restriction is required, solid lane lines or channeliz- ing lines should be extended into or continued through inter- sections or major driveways.” Paragraph 6 of Section 3B.08 contains the following guid- ance: “A single line of equal width to one of the lines of the double line should be used to extend a double line through an intersection.” Use Versus Non-Use of Dotted Lines (23 agencies) The design standards for 13 agencies (CA, IN, MD, MT, NH, NY, OR, PA, SC, WV, DC, CLT, and LAN) state that the use of a dotted line to extend the lane line between the two turn lanes through the intersection is optional. The design standards for Tennessee and Wyoming note that a dotted line is typically used to extend the lane line between the two turn lanes through the intersection. The design standards for eight agencies (CO, FL, ID, NC, RI, VA, WA, and TUC) state that the use of a dotted line to extend the lane line between the two turn lanes through the intersection is required. The design standards for Colorado state that the lane line between the two turn lanes is extended through the intersec- tion using either a dotted or solid line. When dotted lane line extensions are used, the portion of the lane line extension from the stop line to the edge line extended of the cross street is a solid line. The design standards for Idaho note that when the volume of turning vehicles exceeds 200 per hour, a solid line is used (instead of a dotted line) for the extension through the inter- section of the lane line between the two turn lanes. The design standards for Oregon state that the lane line between the two turn lanes may be extended through the intersection using a dotted or solid line. The dotted or solid line may be continued through a marked crosswalk. The design standards for Wyoming state that the lane line between the two turn lanes is typically extended through the intersection using a dotted or solid line. Pattern of Dotted Lines (26 agencies) The following patterns are used for dotted lines that extend the lane line between the two turn lanes through an intersection: WV—0.5-ft segments with 2-ft gaps CA—1-ft segments with 6-ft gaps LAN—1-ft segments with 8-ft gaps CO, FL, HI, ID, KS, MI, NY, PA, RI, TN, VA, DC, CLT—2-ft segments with 4-ft gaps IN—typically 2-ft segments with 4-ft or longer gaps, with a segment-to-gap ratio of no greater than 1 to 4 SC—2-ft segments with 5-ft gaps NH, OR, WA, WY, TUC—2-ft segments with 6-ft gaps MT—typically 2-ft segments with 8-ft gaps NC—2-ft segments with 8- or 13-ft gaps MD—3-ft segments with 9-ft gaps. Width of Dotted Lines (7 agencies) The following widths are explicitly specified in the design standards for dotted lines that extend the lane line between the two turn lanes through an intersection: CA, HI, NY, WV, DC, TUC—4 in. TN—8 in. Other Considerations Regarding Lane Line Extensions for Dual Turn Lanes (4 agencies) The design standards for Colorado require that the lane line separating the right-most left-turn lane from the adjacent through lane be extended into the intersection just far enough to allow left-turning vehicles in opposite directions to miss each other by at least 4 ft. The design standards for Florida state that the centerline or edge line on the left-hand side or the lane line on the right-hand

side of the turn lanes may be extended through the intersec- tion using dotted lines if engineering judgment indicates that this would be helpful to drivers. The design standards for Indiana require that if dual left- turn lanes are provided in opposing directions, the dotted line extensions of the lane lines between the two turn lanes should be separated from each other in the center of the intersection by at least 30 ft. The design standards for the city of Tucson/Pima County require that if dual left-turn lanes are provided in opposing directions, the dotted line extensions of the lane lines between the two turn lanes should typically be separated from each other in the center of the intersection by at least 26 ft. USE AND TYPE OF DOTTED LINES IN TURN LANE TAPERS Figure 2 shows an example of a dotted line in a turn lane taper. 2003 MUTCD Provisions The MUTCD does not require or recommend that dotted lines be used in turn lane tapers to discourage through traffic from unintentionally entering the turn lane. None of the fig- ures in Part 3 that show the formation of a turn lane at an intersection (see Figures 3B-2, 3B-7, 3B-11, and 3B-22) show dotted lines in the turn lane tapers. However, the MUTCD does not prohibit dotted lines from being used for this purpose (see Appendix A for figures). Item E in Paragraph 1 of Section 3A.05 contains the fol- lowing standards: “A dotted line shall consist of noticeably shorter line segments separated by shorter gaps than used for a broken line. The width of a dotted line shall be at least the same as the width of the line it extends.” Even though these provisions are classified as requirements they do not specify the width or the pattern of dotted lines, which varies signifi- cantly among the policies of the various agencies. Paragraph 3 of Section 3A.05 contains the following option: “A dotted line for line extensions may consist of 2 ft line segments and 2 ft to 6 ft gaps.” Use Versus Non-Use of Dotted Lines (43 agencies) The design standards for 30 agencies (AK, AZ, AR, CA, CO, ID, KS, KY, MD, MI, MN, MS, MT, NE, NV, NH, NY, OK, PA, SC, SD, TN, TX, UT, WA, WV, WI, PR, LAN, and TUC) do not show dotted lines in turn lane tapers. The design standards for Colorado specify that dotted lines are not to be used in turn lane tapers. The design standards for Idaho show a dotted line only in the taper of a left-turn lane formed by widening between the through lanes on a two-way highway. (The design standards for Maryland show the upstream end 16 of a dotted line instead of a solid line at the upstream end of the full-width turn lane.) The design standards for three agencies (OH, OR, and WY) note that dotted lines are optional in turn lane tapers. The design standards for Florida note that dotted lines are not typically used in turn lane tapers. However, in curves or in other areas where drivers in the through lane might need extra guidance to avoid unintentionally drifting into a turn lane, a broken lane line (6-ft segments with 10-ft gaps) may be used. The design standards for Virginia note that dotted lines are used if the distance between the upstream end of the turn lane taper and the upstream end of the lane line separating the turn lane from the adjacent through lane is longer than 100 ft. If the distance between the upstream end of the turn lane taper and the upstream end of the lane line separating the turn lane from the adjacent through lane is 100 ft or less, a dotted line is not used. The design standards for the District of Columbia state that dotted lines are used where a turn lane occurs on a hori- zontal curve. The design standards for seven agencies (AL, DE, GA, NC, RI, VT, and CLT) specify that dotted lines are to be used in all turn lane tapers. Pattern of Dotted Lines (12 agencies) The following patterns are used for dotted lines in turn lane tapers: AL, RI, VT, VA, DC—2-ft segments with 4-ft gaps DE, GA, OR, WY—2-ft segments with 6-ft gaps CLT—2-ft segments with 10-ft gaps NC—2-ft segments with 13-ft gaps FL—6-ft segments with 10-ft gaps. Width of Dotted Lines (6 agencies) The following widths are used for dotted lines in turn lane tapers: AL, VT, WY—4 in. AL—4 to 6 in. GA—5 in. DC—8 in. LEFT-TURN LANE ADDED BETWEEN THROUGH LANES OF TWO-LANE HIGHWAYS Figure 5 shows examples of adding a left-turn lane between the through lanes of two-lane highways.

17 2003 MUTCD Provisions The MUTCD does not include an illustration of adding a left- turn lane between the through lanes on a two-lane highway, nor does it address the length of left-turn lane tapers. How- ever, the following formulas are recommended in several places in Part 3 (Paragraph 10 of Section 3B.03, Paragraph 2 of Section 3B.09, Paragraph 2 of Section 3B.10, and Figures 3B-12 and 3B-13) for the length (L) in feet of a shifting taper for through traffic: L = WS for speeds of 45 mph or more and L = WS2/60 for speeds of less than 45 mph, where W is the width of the offset distance in feet and S is the speed of traf- fic in mph (see Appendix A for figures). Shifting Taper (21 agencies) The design standards for 15 agencies (AZ, AR, CA, ID, KS, MI, MO, NH, OH, PA, SD, TN, TX, WY, and TUC) use the recommended MUTCD formulas for the length of the shifting taper for the through lane as it approaches the left-turn lane location. However, one of these agencies (CA) allows the speed (S) in urban areas to be reduced by 10 to 20 mph. In the design standards for Oregon the recommended MUTCD formulas are used but the threshold between the use of the high-speed formula versus the low-speed formula is 35 mph instead of 45 mph. In the design standards for Washington State the recom- mended MUTCD high-speed formula (L = WS) is used for all speeds, even low speeds. In the design standards for Utah the recommended MUTCD formulas are used to compute L, but only half of L is used for the shifting taper. In the design standards for Montana the length of the shift- ing taper is calculated from a taper rate based on design speed and is shown in a chart. The shifting taper rate varies from 10-to-1 for 20 mph (shown as 30 km/h) to 75-to-1 for 70 mph (shown as 120 km/h). The design standards for Iowa and Louisiana show reverse curves being used to transition from a two-lane section to a three-lane section of roadway. The Iowa design standards specify 12,000 ft for the radii of the reverse curves. The Louisiana design standards do not specify the radii of the reverse curves. (The Louisiana design standards also show a reverse curve being used to transition from a three-lane sec- tion back to a two-lane section on the departure side of the intersection.) Amount of Widening (21 agencies) The design standards for 17 agencies (AZ, CA, IA, KS, LA, MI, MO, MT, NH, OH, OR, PA, TX, UT, WA, WY, and TUC) use the shifting taper to widen the roadway until the full- width of the turn lane becomes available. These are known as fully shadowed left-turn lanes. The design standards for four agencies use the shifting taper to widen the roadway until less than the full-width of the turn lane becomes available. These are known as partially shadowed left-turn lanes. In all four cases, the upstream end of the left-turn lane taper begins at the point where the partial width of the turn lane first becomes avail- able. The following are the amounts of partial widening that occur: ID—half of the width of the left-turn lane AR, SD—two-thirds of the width of the left-turn lane TN—three-fourths of the width of the left-turn lane. Distance from Full Shadowing to Upstream End of Left-Turn Taper (17 agencies) The design standards for 13 of the 17 agencies that use fully shadowed left-turn lanes (AZ, CA, IA, KS, LA, MI, MO, MT, NH, OR, WA, WY, and TUC) show the upstream end of the left-turn lane taper beginning at the point where the full width of the turn lane first becomes available. The design standards for four agencies do not show the upstream end of the left-turn lane taper beginning at the point where the full width of the turn lane first becomes available. The following are the distances between the point where the full width of the turn lane first becomes available and the upstream end of the left-turn lane taper for these four agencies: UT—20 ft OH—100 ft PA—half of the shifting taper TX—unspecified distance. Length of Left-Turn Taper (21 agencies) The design standards for 14 agencies show a straight-line left-turn taper. The following lengths are shown for straight- line left-turn tapers: OH—50 ft NH—75 ft if the posted speed limit is 40 mph or less and 100 ft if the posted speed limit is 45 mph or more MO—100 ft CA—120 ft in high-speed rural areas and 60 or 90 ft in business, residential, or urban areas WY—150 ft PA—one-sixth of the shifting taper AR—one-third of the shifting taper IA—10-to-1 taper rate MT—the taper rate, which varies from 8-to-1 for 20 mph (shown as 30 km/h) to 18-to-1 for 70 mph (shown as

120 km/h), is based on design speed and is shown in a table WA—the length, which varies from 75 ft for a 25 mph speed limit to 180 ft for a 60 mph speed limit, is based on the posted speed limit and is shown in a table SD, TN, TX, UT—unspecified length. The design standards for three agencies show a left-turn taper comprised of reverse curves. The following lengths are shown for reverse-curve left-turn tapers: ID—length in feet is five times the speed limit in mph KS—unspecified length (reverse curves with a radius of 150 ft for speeds of 40 mph or less and 300 ft for speeds of 45 mph or more are used to form the left-turn lane taper) LA—unspecified length. The design standards for three agencies show a gap in the lane line on the left-hand side of the approach through lane instead of a marked taper (see Figure 6). The only longitudi- nal pavement marking in the gap area is the centerline adja- 18 cent to the departure lane in the opposite direction. The fol- lowing lengths are shown for the gaps in the lane line: AZ—60 ft if the posted or design speed is less than 40 mph, 90 ft if the posted or design speed is 40 to 50 mph, and 140 ft if the posted or design speed is more than 50 mph TUC—60 ft if the posted speed limit is 35 mph or less, 90 ft if the posted speed limit is 40 or 45 mph, and 120 ft if the posted speed limit is 50 mph or more MI—at least 75 ft. The design standards for Oregon show two options for providing a left-turn taper. One option is to use a set of reverse curves with the length of the reverse curves, which varies from 98 ft for 35 mph to 180 ft for 65 mph, based on design speed and shown in a table. A second option, which uses the same length as the reverse curves, is to extend the double yellow centerline on the left-hand side of the approach through lane for one-eighth of the length and then leave a gap in the lane line on the left-hand side of the approach through lane instead of a marked taper. FIGURE 6 Gap in lane line instead of marked taper (Source: Michigan DOT pavement markings typical plans).

19 SOLID LANE LINES BETWEEN THROUGH LANES ON SIGNALIZED APPROACHES Figure 4 shows an example of a solid lane line between the through lanes on a signalized approach. 2003 MUTCD Provisions Paragraph 5 of Section 3B.04 contains the following option: “[Solid white lane line markings] may also be used to sepa- rate traffic lanes approaching an intersection.” Drawing “b” in Figure 3B-11 illustrates the use of solid lane lines between through lanes on the approach to an intersection. Drawings “c” and “d” in Figure 3B-11 illustrate using broken lane lines between through lanes on the approach to an intersection (see Appendix A for figures). Use Versus Non-Use of Solid Lane Lines Between Through Lanes (42 agencies) The design standards for 29 agencies (AL, AR, CA, CO, GA, ID, IL, IN, KS, KY, MD, MI, MO, NV, NY, NC, OH, OR, SC, TN, TX, VT, WA, WI, WY, PR, CLT, NYC, and TUC) consistently show the use of broken lane lines between through lanes on the approaches to intersection stop lines. The design standards for Maryland specifically state, “Lane lines between through lanes should not be con- verted to solid lines on the approaches to intersections, except in critical areas where it is advisable to discourage lane changing.” The design standards for Delaware and Montana show the use of either solid lane lines or broken lane lines between through lanes on the approaches to intersection stop lines. The design standards for 11 agencies (AK, CT, FL, OK, PA, SD, UT, VA, WV, DC, and LAN) consistently show the use of solid lane lines between through lanes on the approaches to intersection stop lines. Length of Solid Lane Lines Between Through Lanes (13 agencies) The following are the lengths of the solid lane lines between through lanes on the approaches to intersection stop lines for the 13 agencies that allow or require them: UT—27 ft (shown as 8 m) CT, FL, OK, LAN—50 ft DC—90 ft VA, WV—100 ft PA—150 ft AK—300 ft in urban areas and 500 ft in rural areas SD—equal to the length of any full-width turn lanes adja- cent to the through lanes DE, MT—unspecified. Width of Solid Lane Lines Between Through Lanes (13 agencies) The following are the widths of the solid lane lines between through lanes on the approaches to intersection stop lines for the 13 agencies that allow or require them: AK, CT, OK, MT, SD, WV—4 in. PA—4 or 6 in. DC—6 in. DE, FL, UT, VA, LAN—unspecified. CROSSWALKS 2003 MUTCD Provisions Paragraph 4 of Section 3B.17 contains the following stan- dard: “When crosswalk lines are used, they shall consist of solid white lines that mark the crosswalk. They shall be not less than 6 in. or greater than 24 in. in width.” The color and that the lines must be solid lines are specified, but flexibility is given regarding the width that may be used, and no stan- dards are given regarding the width of the crosswalk or the layout of the lines. Paragraph 5 of Section 3B.17 contains the following guid- ance: “If transverse lines are used to mark a crosswalk, the gap between the lines should not be less than 6 ft. If diagonal or longitudinal lines are used without transverse lines to mark a crosswalk, the crosswalk should be not less than 6 ft wide.” Paragraphs 12 through 14 of Section 3B.17 contain the following guidance and options: “For added visibility, the area of the crosswalk may be marked with white diagonal lines at a 45-degree angle to the line of the crosswalk or with white longitudinal lines parallel to traffic flow, as shown in Figure 3B-16. When diagonal or longitudinal lines are used to mark a crosswalk, the transverse crosswalk lines may be omitted. This type of marking may be used at locations where substantial numbers of pedestrians cross without any other traffic control device, at locations where physical conditions are such that added visibility of the crosswalk is desired, or at places where a pedestrian crosswalk might not be expected. If used, the diagonal or longitudinal lines should be 12 to 24 in. wide and spaced 12 to 60 in. apart. The marking design should avoid the wheel paths, and the spacing should not exceed 2.5 times the line width.” Figure 3B-16 shows three examples of crosswalk mark- ings: a standard crosswalk comprised of two parallel trans- verse lines, a high-visibility crosswalk comprised of longitu- dinal lines without the transverse lines, and a high-visibility crosswalk comprised of diagonal lines between two trans- verse lines. Paragraph 15 of Section 3B.17 contains the following option: “When an exclusive pedestrian phase that permits diagonal

crossing is provided at a traffic control signal, a marking as shown in Figure 3B-17 may be used for the crosswalk.” Figure 3B-17 shows an example of crosswalk markings that allow diagonal crossing of the intersection. The mark- ings are comprised of four standard crosswalks, but the trans- verse lines closest to the intersection are interrupted at each corner to communicate to pedestrians that a diagonal cross- ing is permitted. The figure includes a note that mentions that the transverse lines closest to the intersection may be omit- ted, which would leave only one transverse line across each leg of the intersection (see Appendix A for figures). Use of Standard and High-Visibility Crosswalks (50 agencies) For the purposes of this synthesis, the following definitions for standard and high-visibility crosswalks will apply. Standard crosswalks are those crosswalks that are marked by two paral- lel transverse lines only. High-visibility crosswalks are those crosswalks that are marked by longitudinal or diagonal lines with or without the transverse lines. Figure 7 shows examples of the various crosswalk types. The design standards for 33 agencies (AL, AK, AZ, AR, CO, DE, FL, ID, IL, IA, KS, MD, MI, MN, MO, MT, NE, NH, NY, NC, OK, OR, PA, RI, TN, TX, UT, WV, DC, PR, LAN, NYC, and TUC) indicate that both standard cross- walks and high-visibility crosswalks are available for use. 20 The design standards for nine agencies (CA, IN, KY, ME, ND, OH, SC, WI, and CLT) show the use of standard cross- walks only. The design standards for eight agencies (CT, GA, HI, NV, SD, VT, WA, and WY) show the use of high-visibility cross- walks only. The design standards for Alabama recommend that high- visibility crosswalks be used for school crosswalks. The design standards for Alaska recommend that standard crosswalks be used at signals and on approaches controlled by STOP signs, and that high-visibility crosswalks be used for all other locations. The design standards for Colorado recommend that high- visibility crosswalks be used at complicated and/or channel- ized intersections and at midblock crosswalks. The design standards for Illinois state that because midblock crosswalks are generally unexpected by the motorist, diago- nal or longitudinal lines should be used in marking midblock crosswalks. The design standards for Maryland note that high-visibility crosswalks may be used across roadways where the speed limit is greater than 35 mph, at midblock locations, at unex- pected locations, and at school crosswalks. The design standards for Rhode Island specify that stan- dard crosswalks are the only type of crosswalk that can be used at intersections, and that high-visibility crosswalks should be used at midblock crosswalks. The design standards for Utah state that the high-visibil- ity crosswalk with the longitudinal lines is used for school crossings, and that the high-visibility crosswalk with the diagonal lines is used only when permitted by the region traf- fic engineer. Minimum Width of Crosswalks (45 agencies) The design standards for the 45 agencies that specify a min- imum crosswalk width use the following minimum widths: IA—6 ft (measured to the outside edges of the transverse crosswalk lines) NH—6 ft (shown as 2 m, and measured from center to center of the transverse crosswalk lines) NY—6 ft (shown as 2 m) DE, ID, IN, KY, ME, MD, MN, MO, NE, ND, OH, PA, SC, TX, VT, WI—6 ft MI—6 ft, but crosswalks at intersections are the same width as the adjacent sidewalk MT—6 ft, but 8 ft is the normal width (a) Standard crosswalk (b) High-visibility crosswalks Diagonal line Longitudinal line Transverse line FIGURE 7 Examples of crosswalks.

21 FL, OR—6 ft, but 10 ft is desirable KS—6 ft for standard and 8 ft for high visibility CO—6 ft for standard and 8 to 10 ft for high visibility NC, TN—6 ft for standard and 10 ft for high visibility GA—6 ft 8 in. or the width of the sidewalk, whichever is greater, but the edge of the crosswalk should not be more than 1 ft beyond the edge of the sidewalk OK, SD, UT, WA—8 ft CT—8 ft at intersections and 10 ft at midblock locations NYC—8 to 18 ft AL, AK, AR, NV, CLT, TUC—10 ft AZ—10 ft at intersections and 15 ft at midblock locations HI—typically 10 ft WY—12 ft DC—15 ft unless otherwise noted on the plans, and 20 ft in the downtown central business district LAN—15 ft, but 20 ft in high pedestrian areas and on the receptive leg of dual left turns (to provide a better turn- ing radius). Width of Transverse Crosswalk Lines (40 agencies) The design standards for the 40 agencies that specify a trans- verse line width use the following widths: IN, ME, MI, MO, NE, NH, ND, WI, DC—6 in. MN—6 to 12 in. KY—6 or 12 in. IA, PA—6 to 24 in. WV—6 to 24 in., with the 24-in. lines used where no stop line is present, where speeds are more than 35 mph, or where crosswalks are unexpected MT—8 in. is the normal width, 6 in. is the minimum width, and 24 in. may be used in areas where posted speed limits exceed 35 mph (shown as 60 km/h), where a stop line is not provided, and in areas where crosswalks would not normally be expected GA, NC, OK, SC, TN, CLT—8 in. HI—at least 8 in. AL, AZ, AR, FL, ID, KS, MD, NY, TX, UT, VT, NYC— 12 in. OR—12 in., but 18 in. wide on state highways with posted speed limits of 55 mph or more CO—12 in., but 24 in. wide if no stop line is provided TUC—12 in., but 24 in. wide on approaches controlled by STOP signs with speed limits of 45 mph or more OH—12 in., but 24 in. wide at midblock locations CA—12 to 24 in. AK—24 in. Design of High-Visibility Crosswalks (38 agencies) Except for 17 agencies, the design standards for those agen- cies that show high-visibility crosswalks consistently show the use of longitudinal lines only (without transverse lines). The design standards for the following agencies illustrate a different design requirement or option for high-visibility crosswalks: NY, TX, NYC—transverse lines may be used AL, AZ, GA, HI, ID, TUC—transverse lines are used MD—transverse lines are used and 45° diagonal lines may be used IA, NH—transverse lines may be used and 45° diagonal lines may be used UT—45° diagonal lines may be used PA—45° diagonal lines with transverse lines may be used RI, VT—45° diagonal lines with transverse lines are used WV—45° diagonal lines are used and transverse lines may be used. Width of Longitudinal and Diagonal Lines (38 agencies) The design standards for the 38 agencies that specify the widths of longitudinal or diagonal lines for high-visibility crosswalks use the following widths: FL, MI, RI, VT, NYC—12 in. TUC—at least 12 in. CO, IA, MD, PA, TX, WV—12 to 24 in. WY—12 to 24 in., but 18 in. is standard CT—16 in., but 24 in. wide for school, elderly, and hand- icapped crosswalks HI—16 in. set of lines (three 4-in.-wide lines separated by gaps of 2 in.) AL, AZ, ID, KS, MT, NE, NV, NH, NY, NC, OK, SD, TN, UT, DC, LAN, TUC—24 in. OR—24 in., or a 36-in. set of lines (two 12-in.-wide lines separated by a gap of 12 in.) WA—24 in., or a 24-in. set of lines (two 8-in.-wide lines separated by a gap of 8 in.) GA—24 in. set of lines (two 8-in.-wide lines separated by a gap of 8 in.) AK, MN—24 to 36 in. MO—30 to 36 in. Spacing of Longitudinal and Diagonal Lines (37 agencies) The design standards for the 37 agencies that specify the spaces (the unmarked gap between the nearest edges of the lines) between longitudinal or diagonal lines for high-visibility crosswalks use the following spacings: MD, TX, WV—12 to 24 in. IA—12 to 24 in. to avoid wheel paths PA—12 to 60 in. CT—16 in., but 24 in. wide for school, elderly, and hand- icapped crosswalks AL, AZ, FL, ID, MI, MT, NH, NC, SD, TN, UT, VT, DC, NYC—24 in.

AK—24 to 36 in. to avoid wheel paths HI—28 in. RI—30 in. MO—30 to 36 in. to avoid wheel paths (the widths of the longitudinal lines and the spaces between them are based on the lane width, with 30-in. lines and 30-in. spaces for 10-ft-wide lanes, 33-in. lines and 33-in. spaces for 11-ft-wide lanes, and 36-in. lines and 36-in. spaces for 12-ft wide lanes) MN—30 to 42 in. to avoid wheel paths (the widths of the longitudinal lines and the spaces between them are spec- ified in a chart that is based on the width of the inside through lane) OK—36 in. NY—48 in. WY—48 to 60 in. to avoid wheel paths OR—centered on lane lines and centers of approach lanes to avoid wheel paths, with a minimum spacing of 36 in. and a maximum spacing of 48 in. TUC—centered on lane lines and centers of approach lanes to avoid wheel paths, with an approximate spac- ing of 48 in. NE—centered on lane lines and centers of approach lanes to avoid wheel paths, with a maximum spacing of 48 in. WA—centered on lane lines and centers of approach lanes to avoid wheel paths, with a maximum spacing of 60 in. CO, GA, KS, LAN—centered on lane lines and centers of approach lanes to avoid wheel paths NV—centered on lane lines and centers of approach lanes to avoid wheel paths in District 1, and 24 in. in Dis- tricts 2 and 3. Other Considerations Regarding Standard and High-Visibility Crosswalks (6 agencies) The design standards for Tennessee require that the nearest edge of the crosswalk line be located at least 2 ft from the extended edge line of the street that is parallel to the crosswalk. The design standards for Arkansas require that crosswalks be located at least 3 ft from the extended edge line of the street that is parallel to the crosswalk. The design standards for Arizona and California require that crosswalks near schools be yellow, and that the nearest edge of the crosswalk line be located at least 6 ft from the extended edge line of the street that is parallel to the crosswalk. The design standards for West Virginia require that the outside edges of crosswalks (the edge of the crosswalk far- thest from the intersection) be at least 6 ft from the extended edge line of the street that is parallel to the crosswalk. The design standards for Washington note that when 24-in.-wide longitudinal lines are used for a high-visibility crosswalk, a 12-in.-wide longitudinal line may be placed on paved shoulders that are 4 ft wide or less to extend the cross- 22 walk to the edge of the pavement. A 24-in.-wide longitudi- nal line may be placed on paved shoulders that are more than 4 ft wide to extend the crosswalk to the edge of the pavement. When two 8-in wide longitudinal lines that are separated by an 8-in. space are substituted for the 24-in.-wide longitudinal lines, an 8-in.-wide longitudinal line may be placed on paved shoulders that are 4 ft wide or less to extend the crosswalk to the edge of the pavement. Other Types of Crosswalks (3 agencies) The design standards for Connecticut, Ohio, and Pennsylva- nia show special crosswalk markings that may be used for an exclusive pedestrian signal phase where all vehicles are stopped and pedestrians can cross all legs of the intersection or can cross diagonally. These markings feature a single line that completely crosses each leg of the intersection. The design standards for Connecticut specify that these lines are 24 in. wide. STOP LINES 2003 MUTCD Provisions Paragraph 1 of Section 3B.16 contains the following stan- dard: “If used, stop lines shall consist of solid white lines extending across approach lanes to indicate the point at which the stop is intended or required to be made.” The color and that the line must be a solid line are specified, but no stan- dards are given regarding the use or width of the line. Paragraph 3 of Section 3B.16 contains the following guid- ance: “Stop lines should be 12 to 24 in. wide.” Use Versus Non-Use of Stop Lines (46 agencies) Except for four agencies, the design standards consistently require stop lines to be used for all signalized approaches. The design standards for Alaska show that the transverse crosswalk line nearest to the approach lane also serves as the stop line for the approach. The design standards for Oregon state that when standard crosswalks are used, the transverse line nearest to the approach lane is used as the stop line. The design standards for the city of Los Angeles state that where crosswalks are present, the transverse crosswalk line nearest to the approach lane serves as the stop line (the lane lines on the approach and departure end at the transverse crosswalk line nearest to the approach lane, and the centerline crosses through standard crosswalks and ends at the transverse cross- walk line closest to the intersection). The design standards for Nebraska note that stop lines are used if needed. Width of Stop Lines (43 agencies) The design standards for the 43 agencies that specify a stop line width use the following widths:

23 AR, NE, UT, WV, HI—12 in. CT—at least 12 in. CA, ME, MN—12 to 18 in. in urban areas and 18 to 24 in. in rural areas OR, PA—12 to 24 in. KY—12 or 24 in. TUC—12 in., but 24 in. wide on approaches controlled by STOP signs with speed limits of 45 mph or more DE—16 in. MD—16 in. for approach speed limits of 35 mph or less and 24 in. for approach speed limits more than 35 mph AZ, NH—18 in. WI—typically 18 in., but can vary from 12 to 24 in. NY—18 in., but designer may also specify 12 or 24 in. AL, CO, FL, ID, IN, IA, KS, LA, MI, MO, MT, NV, NC, ND, OH, OK, SC, SD, TN, TX, VT, VA, WY, NYC—24 in. Placement of Stop Lines (38 agencies) The design standards for the 38 agencies that specify a stop line placement use the following distances from the adjacent crosswalk: MI, MO, NE, NY, OK, PA, SD, WA—4 ft NH, ND, TX, UT, TUC—typically 4 ft AZ, AR, CA, CO, CT, FL, ID, IN, IA, KY, LA, ME, MD, MT, NV, NC, SC, TN, VT, VA, WI—at least 4 ft WY—4 to 30 ft NYC—5 ft (and STOP messages are placed in approach lanes such that the top of the letters is 10 ft upstream from the stop line) AL, KS—at least 5 ft. RIGHT-TURN CHANNELIZING ISLANDS Figure 8 shows examples of right-turn channelizing islands and their associated pavement markings. 2003 MUTCD Provisions Paragraph 2 of Section 3B.05 contains the following option: “Channelizing lines may be used to form channelizing islands where traffic traveling in the same direction is per- mitted on both sides of the island.” Paragraph 3 of Section 3B.05 contains the following stan- dard: “Other pavement markings in the channelizing island area shall be white.” Thus, the color of the markings in chan- nelizing islands is specified, but not their use, width, or pattern. Paragraph 9 of Section 3B.10 contains the following option: “If traffic can pass either to the right or left of the obstruction, additional white markings may be placed in the neutral area between the channelizing lines as shown in Fig- ure 3B-13” (see Appendix A for figures). Width of Lines That Mark the Edges of Right-Turn Channelizing Islands (18 agencies) The design standards for the 18 agencies that specify a line width for the channelizing lines that mark the edges of right- turn channelizing islands use the following widths: PA—4 in. MI—6 in. for painted islands and 12 in. for approaches to raised islands WV—6 in. to 8 in. AK, AR, CO, FL, GA, HI, IN, IA, MT, OK, UT, WY—8 in. Edge of island Chevron Edge of island diagonal lines island Chevrons (a) Right-turn channelizing island using pavement markings only (b) Right-turn channelizing island using a raised island FIGURE 8 Examples of right-turn channelizing islands.

WI—8 in. on approaches to raised islands only (the lines extend only 5 ft beyond the nose of the island) TN—8 in. if the area of the island is 400 ft2 or less or if the island is raised, and 24 in. if the area of the painted island is more than 400 ft2 VT—48 in. if the area of the island is 450 ft2 or more (if the area of the island is less than 450 ft2, the island is painted in its entirety). Width of Lines Within Right-Turn Channelizing Islands (18 agencies) The design standards for the 18 agencies that specify a line width for the diagonal lines or chevrons within right-turn channelizing islands use the following widths: MI—6 in. when the speed is 45 mph or less and 12 in. when the speed is more than 45 mph IA, NC, OK, UT—8 in. CA, HI, IN, RI, WV, DC, CLT—12 in. TN—12 in. if area of island is 400 ft2 or less or if island is raised and more than 6 ft of pavement width exists between the edge line and the raised island, otherwise no markings are used within the island AK, FL—18 in. GA, OH, SC—24 in. Spacing of Lines Within Right-Turn Channelizing Islands (16 agencies) The design standards for the 16 agencies that specify the spacing (the unmarked gap between the nearest edges of the lines) of the diagonal lines or chevrons within right-turn channelizing islands use the following spacings: DC—5 ft SC, WV—6 ft AK—7 ft FL, OK, UT—10 ft TN—10 ft if area of island is 400 ft2 or less or if island is raised and more than 6 ft of pavement width exists between the edge line and the raised island, otherwise no markings are used within the island 24 IL—10 ft for speed limits less than 30 mph, 15 ft for speed limits from 30 to 45 mph, and 20 ft for speed limits more than 45 mph (in all of these cases, if the recom- mended spacing does not provide at least five 12-in.- wide diagonal lines in the area being marked, the spac- ing from the next lowest speed range should be used) OH—12 ft GA—15 ft HI, IN, IA, MI—20 ft NC—equal in feet to the posted speed limit in mph. Other Considerations Regarding Right-Turn Channelizing Islands (9 agencies) The design standards for Arkansas, Colorado, Vermont, and Wyoming specify that no diagonal lines or chevrons be used within right-turn channelizing islands. The design standards for Colorado show raised right-turn channelizing islands being marked by 8-in.-wide solid lines on both sides of the gore area leading up to the island, and along the left edge line of the right-turn lane from the point where the island ends to the point where the line intersects the right edge line of the intersecting roadway. The rest of the raised island is surrounded by 4-in.-wide edge lines. There are no markings between the raised island and the 4-in.-wide edge lines or 8-in.-wide solid lines. The design standards for Montana state that diagonal lines or chevrons are not used on the paved portion between the edge lines and raised islands. The curbs of the raised right- turn channelizing islands are painted yellow. The design standards for Oklahoma and Pennsylvania note that diagonal lines or chevrons are not used on the paved portion between the edge lines and raised islands. The design standards for Oregon state that diagonal lines or chevrons are optional in right-turn channelizing islands. The design standards for Utah show that diagonal lines or chevrons are only placed in the painted island area before the raised portion of the island and in the painted island area after the raised portion of the island.

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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 356: Pavement Markings—Design and Typical Layout Details identifies variations in pavement marking designs, practices, and policies, as provided by 48 of 50 state departments of transportation, and transportation agencies from the District of Columbia, Puerto Rico and four cities.

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