2 Del. Admin. Code § 3B.09
Current through Register Vol. 28, No. 5, November 1, 2024
Section 3B.09 - Lane-Reduction Transition MarkingsSupport:
01 Lane-reduction transition markings are used where the number of through lanes is reduced because of narrowing of the roadway or because of a section of on-street parking in what would otherwise be a through lane. Lane-reduction transition markings are not used for lane drops. Standard:
02 Except as provided in Paragraph 3, where pavement markings are used, lane-reduction transition markings shall be used to guide traffic through transition areas where the number of through lanes is reduced, as shown in Figure 3B-14. On two-way roadways, no-passing zone markings shall be used to prohibit passing in the direction of the convergence, and shall continue through the transition area. Option:
03 On low-speed urban roadways where curbs clearly define the roadway edge in the lane-reduction transition, or where a through lane becomes a parking lane, the edge line and/or delineators shown in Figure 3B-14 may be omitted as determined by engineering judgment. Guidance:
04 For roadways having a posted or statutory speed limit of 45 mph or greater, the transition taper length for a lane-reduction transition should be computed by the formula L = WS. For roadways where the posted or statutory speed limit is less than 45 mph, the formula L = WS2/60 should be used to compute the taper length. 04A (DE Revision) Lane-reduction transition markings along interstates, freeways, and expressways should be installed as shown in Figure 3B-14A. Lane-reduction transition markings beyond intersections should be installed as shown in Figures 3B-14B and 3B-14C. Option:
04B (DE Revision) Lane-reduction markings shown in Figures 3B-14A, 3B-14B, and 3B-14C may be adjusted based on engineering judgment at existing locations where space is limited due to site-specific conditions. Support:
05 Under both formulas, L equals the taper length in feet, W equals the width of the offset distance in feet, and S equals the 85th-percentile speed or the posted or statutory speed limit, whichever is higher. Guidance:
06 Where observed speeds exceed posted or statutory speed limits, longer tapers should be used. Option:
07 On new construction, where no posted or statutory speed limit has been established, the design speed may be used in the transition taper length formula. Guidance:
08 (DE Revision) Lane line markings should be discontinued where the transition taper begins.09 Except as provided in Paragraph 3 for low-speed urban roadways, the edge line markings shown in Figure 3B-14 should be installed from the location of the Lane Ends warning sign to beyond the beginning of the narrower roadway. Support:
2 Del. Admin. Code § 3B.09