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32 of the broken lane line to the downstream end of the transi- the lane placed at a distance D upstream from the upstream end tion taper. of the transition taper. At least two additional lane-reduction arrows are placed upstream of the arrow nearest to the down- stream end of the lane. The distance from the center of one Use of Lane-Reduction Arrows (31 agencies) arrow to the center of the next arrow is 300 ft on conventional The design standards for 17 agencies (AZ, AR, CO, DE, GA, roadways and 600 ft on expressways and freeways. IN, IA, LA, MA, MN, NY, ND, TN, UT, VT, WY, and PR) do not show the use of lane-reduction arrows in the lane that The design standards for the city of Charlotte show the is ending. tops of the lane-reduction arrows positioned as follows: 25 ft downstream from the upstream end of the transition taper, at The design standards for three agencies (ID, MI, and OR) the upstream end of the transition taper, at 50 ft upstream state that the use of lane-reduction arrows in the lane that is from the upstream end of the transition taper, and at 100 ft ending is optional. The design standards for Michigan also upstream from the upstream end of the transition taper. require a MERGE message to be placed just upstream of each lane-reduction arrow if lane-reduction arrows are used. The The design standards for the city of Tucson/Pima County design standards for Oregon note that lane-reduction arrows show the lane-reduction arrow farthest upstream positioned are optional for speeds higher than 45 mph, but are generally with its top a distance in feet upstream from the upstream end not used for speeds of 45 mph or less. of the transition taper that is calculated using the formula 15(S - 25) + 250, where S is the posted speed in mph. Two The design standards for 11 agencies (CA, FL, KY, MD, additional lane-reduction arrows are placed downstream MS, NV, NC, PA, CLT, LAN, and TUC) require the use of from this arrow at 40-ft intervals for speed limits of 30 mph or lane-reduction arrows in the lane that is ending. The design less, 80-ft intervals for 35 or 40 mph speed limits, and 120-ft standards for Florida also require a MERGE message to be intervals for speed limits of 45 mph or more. placed just upstream of each lane-reduction arrow. The other nine agencies that use lane-reduction arrows in Number and Placement of Lane-Reduction Arrows the lane that is ending place the top of the arrows at the fol- (14 agencies) lowing distances upstream from the upstream end of the tran- sition taper: The 14 agencies that use lane-reduction arrows in the lane that is ending use the following number of arrows: CA, ID, LAN--0 ft, 200 ft, and 400 ft NC--0 ft, 100 ft, 200 ft, 500 ft, and 800 ft FL, MI, MS--2 NV--0, 0.25D, and 0.5D OR--at least 2 KY--0.75D, D, and D + 250 ft CA, ID, KY, MD, NV, LAN, TUC--3 MI--D and 2D PA--at least 3 FL--just before the downstream end of the full-width CLT--4 lane where a painted taper begins (the edge of pave- NC--5. ment taper begins 120 to 910 ft farther downstream The design standards for Maryland show a lane-reduction based on the speed and lateral offset, and at the down- arrow positioned such that the bottom of the arrow is lined stream end of the broken lane line up with the downstream end of the broken lane line. Two OR--typically 500 ft to the first arrow and then additional additional lane-reduction arrows are placed in the lane, one lane-reduction arrows are placed upstream with the in either direction from the lane-reduction arrow that is lined spacing between the bottom of the downstream arrow up with the downstream end of the broken lane line. These and the top of the upstream arrow being 200 ft. additional arrows are placed at a distance (measured from the bottom of one arrow to the bottom of the next arrow) that is PAINTED MEDIANS, PAVED SHOULDERS, based on speed (850 ft for 65 mph, 775 ft for 60 mph, 700 ft AND APPROACHES TO OBSTRUCTIONS for 55 mph, 625 ft for 50 mph, and 550 ft for 45 mph). Figure 9 shows examples of diagonal lines in painted medians The design standards for Mississippi show a lane-reduction and on paved shoulders. Figure 3B-13 (see Appendix A) arrow placed at the halfway point of the 6-in.-wide dotted line shows examples of diagonal lines and chevrons on approaches and the other placed 100 ft upstream of the downstream end of to obstructions. the broken lane line. The lane-reduction arrows are the same shape as the lane use arrows used in straight-through lanes and are positioned at a 30 angle from the lane line. 2003 MUTCD Provisions The design standards for Pennsylvania show the center of Paragraph 6 of Section 3B.03 contains the following standard the lane-reduction arrow nearest to the downstream end of that makes it clear that painted medians do not have to include

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33 Painted median Paved shoulder FIGURE 9 Examples of diagonal lines in painted medians and on paved shoulders. diagonal lines, but that yellow pavement markings (such as The design standards for six agencies (CA, CO, MI, NH, diagonal lines) may be used: "If a continuous median island OR, UT) indicate that diagonal lines are optional within formed by pavement markings separating travel in opposite painted medians. The design standards for Ohio indicate that directions is used, two sets of double solid yellow lines shall diagonal lines are optional, but typically not used within be used to form the island as shown in Figures 3B-2 and 3B-4. painted medians that are less than 6 ft wide. Other markings in the median island area shall also be yellow, except crosswalk markings which shall be white (see Section The design standards for Idaho state that diagonal lines 3B.17)." Although the type of lane line has been made a stan- should not be placed as a standard practice because of the dard, no standards are provided for the use, width, or placement questionable benefits and high exposure of paint crews to of diagonal lines in the painted median area. traffic. Exceptions should be limited to those locations where the additional emphasis is clearly needed and then only for Paragraph 7 of Section 3B.10 contains the following medians with widths of 10 ft or more. option: "If traffic is required to pass only to the right of the obstruction, yellow diagonal approach markings may be The design standards for Pennsylvania note that diagonal placed in the neutral area between the no-passing zone mark- lines are used only when required to provide emphasis if the ings as shown in Figure 3B-13" (see Appendix A for figures). visibility or sight distance is restricted. Paragraph 9 of Section 3B.10 contains the following option: The design standards for Iowa state that if the width of the "If traffic can pass either to the right or left of the obstruction, painted median becomes less than 2 ft the median is painted additional white markings may be placed in the neutral area solid yellow. between the channelizing lines as shown in Figure 3B-13." Width of Diagonal Lines Within Painted Medians Use Versus Non-Use of Diagonal Lines (34 agencies) Within Painted Medians (39 agencies) The design standards for the 34 agencies that specify a line Except for the 12 agencies listed here, the design standards con- width for the diagonal lines (at a forward angle of 45 unless sistently show the use of diagonal lines within painted medians. otherwise stated) within painted medians use the following widths: The design standards for three agencies (AK, AZ, PR) indi- cate that diagonal lines are not used within painted medians. MI--6 in. for posted speed limits of 45 mph or less and The design standards for Tennessee indicate that diagonal lines 12 in. for posted speed limits of more than 45 mph are not used within painted medians that are less than 6 ft wide. CO, IA, NC, OK, UT, VT--8 in.

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34 CA, HI, IL, NE, RI, TN, WV, WI, DC--12 in. limits less than 30 mph, 75 ft for speed limits from 30 OR--12 in. at a 36 angle (the diagonal lines are rectan- to 45 mph, and 150 ft for speed limits of more than gular in shape and do not connect to the lane lines-- 45 mph between intersections (if the recommended the nearest points of the diagonal lines are placed 4 in. spacing does not provide at least five diagonal lines in from the centerline) the area being marked, the spacing from the next low- KS, CLT--12 in. at a 30 angle est speed range should be used) IN--12 in. for posted speed limits of 45 mph or less and MN--20 ft, but may be increased to 30 ft for speeds of 24 in. for posted speed limits of more than 45 mph more than 40 mph (measured perpendicular to the TUC--12 in. for posted speed limits of 40 mph or less and diagonal lines) 24 in. for posted speed limits of more than 40 mph HI, IA, MS, NH, TX--20 ft FL, MS--18 in. OR--20 ft, but may be increased to 40 ft if the distance GA, LA, NH, OH, PA, SC, SD--24 in. between left-turn lanes exceeds 200 ft NY--24 in. at a 45 angle, 12 in. at a 20 angle, or 8 in. IN--20 ft for posted speed limits of 45 mph or less and at a 15 angle 40 ft for posted speed limits of more than 45 mph MT--24 in. at a 30 angle TUC--20 ft for posted speed limits of 40 mph or less and MN--24 in., but may be reduced to 12 in. for speeds less 80 ft for posted speed limits of more than 40 mph than 40 mph LA--24 ft TX--typically 24 in., but no less than 12 in. CO--25 ft MT--25 ft (shown as 7.5 m) Spacing of Diagonal Lines Within Painted Medians WI--25 ft starting when the painted median becomes (33 agencies) 3 ft wide SD--25 ft, but 20 ft for two-lane to four-lane transition The design standards for the 33 agencies that specify the areas spacing (measured along the centerline unless otherwise CLT--30 ft stated) for the diagonal lines within painted medians use the TN--50 ft for posted speed limits of 40 mph or less and following spacings: 100 ft for posted speed limits of more than 40 mph (where a left-turn lane is formed by roadway widen- DC--5 ft ing at an intersection, diagonal lines are spaced at SC--6 ft for the first five diagonal lines, 12 ft for the next 10-ft intervals and start when the width of the median four diagonal lines, and 18 ft for the remaining diago- becomes 6 ft) nal lines (the diagonal lines start when the median NC--the distance in feet is equal to the posted speed limit width reaches 2 ft and end when the median width in mph reaches 8 ft; however, the length of median with diag- KS--the distance in feet is equal to the speed in mph. onal lines spaced at 18-ft intervals is not less than 72 ft or more than 500 ft) VT--7 ft where speeds are low, sight distance is less than Longitudinal Lines Surrounding Painted Medians (39 agencies) 200 ft, and the length of the painted median is 75 ft or less; 14 ft where speeds are high, sight distance is 200 Except for the two agencies listed here, the design standards ft or more, and where the length of the painted median consistently show double yellow centerlines on both sides of is more than 75 ft painted medians. PA--8 ft for posted speed limits of 35 mph or less and 16 ft for posted speed limits of more than 35 mph The design standards for Iowa show 8-in.-wide solid lines RI, UT--10 ft surrounding painted medians. FL, MI--10 to 40 ft based on posted speed limit NY--11 ft (shown as 3.3 m) for 45 angle lines, 12 ft The design standards for Mississippi show 12-in.-wide (shown as 3.6 m) for 20 angle lines, or 10 ft (shown solid lines surrounding painted medians. as 3.0 m) for 15 angle lines WV--12 ft NE--12 ft in urban areas and 20 ft in rural areas Use Versus Non-Use of Diagonal Lines OH--12 ft for the first 48 ft, 24 ft for the next 48 ft, and on Paved Shoulders (20 agencies) 48 ft thereafter (the 12-ft spacing starts on both ends of the painted median) Except for the two agencies cited here, the design standards GA, OK--15 ft consistently show that the use of diagonal lines on paved IL--15 ft for speed limits less than 30 mph, 20 ft for shoulders is optional. speed limits from 30 to 45 mph, and 30 ft for speed limits of more than 45 mph near intersections and in The design standards for Arkansas indicate that diagonal pavement width transition areas; and 50 ft for speed lines are not used on paved shoulders.

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35 The design standards for Idaho note that diagonal lines IL--50 ft for speed limits less than 30 mph, 75 ft for should not be placed as a standard practice because of the speed limits from 30 to 45 mph, and 150 ft for speed questionable benefits and high exposure of paint crews to limits of more than 45 mph (if the recommended spac- traffic. Exceptions should be limited to those locations where ing does not provide at least five diagonal lines in the the additional emphasis is clearly needed and then only for area being marked, the spacing from the next lowest paved shoulders with widths of 10 ft or more. speed range should be used) NY--up to 100 ft for 45 angle lines or 12 ft (shown as 3.6 m) for 20 angle lines or 10 ft (shown as 3.0 m) for Width of Diagonal Lines on Paved Shoulders 15 angle lines (20 agencies) NC, PA--the distance in feet is equal to the posted speed limit in mph, but can be increased to 200 ft or more on The design standards for the 20 agencies that specify a line Interstate highways width for the diagonal lines (at a forward angle of 45 unless KS--the distance in meters is equal to the speed in otherwise stated) on paved shoulders use the following kilometers/hour divided by five. widths: MI--6 in. for posted speed limits of 45 mph or less and Width of Diagonal Lines or Chevrons on 12 in. for posted speed limits of more than 45 mph Approaches to Obstructions (8 agencies) CO, NC--8 in. CA, HI, IL, RI, TN, DC, PR--12 in. The design standards for the eight agencies that specify a line KS, CLT--12 in. at a 30 angle width for the diagonal lines or chevrons (both at a forward NYC--16 in. angle of 45 unless otherwise stated) on approaches to obstruc- tions use the following widths: FL, MS--18 in. GA, NH, OH, PA--24 in. CO--8 in. NY--24 in. at a 45 angle, 12 in. at a 20 angle, or 8 in. at CA, GA, IL, TN, DC--12 in. a 15 angle. KS--12 in. at a 30 angle AK--18 in. Spacing of Diagonal Lines on Paved Shoulders (17 agencies) Spacing of Diagonal Lines or Chevrons on Approaches to Obstructions (6 agencies) The design standards for the 17 agencies that specify the spac- ing (measured along the centerline) for the diagonal lines (at The design standards for the six agencies that specify the a forward angle of 45 unless otherwise stated) on paved shoul- spacing (measured along the centerline or lane line) for the ders use the following spacings: diagonal lines or chevrons on approaches to obstructions use the following spacings: DC--5 ft FL, MI--10 to 40 ft based on posted speed limit GA, DC--5 ft OH--12 ft for the first 48 ft, 24 ft for the next 48 ft, and IL--10 ft for speed limits less than 30 mph, 15 ft for 48 ft thereafter speed limits from 30 to 45 mph, and 20 ft for speed GA--15 to 50 ft limits of more than 45 mph (if the recommended spac- MS, NH--20 ft ing does not provide at least five diagonal lines in the CO--20 to 100 ft area being marked, the spacing from the next lowest CLT--30 ft speed range should be used) PR--33 ft TN--10 ft for posted speed limits of 40 mph or less and HI--40 ft 20 ft for posted speed limits of more than 40 mph TN--50 ft for posted speed limits of 40 mph or less and AK--12 ft 100 ft for posted speed limits of more than 40 mph CO--25 ft.