Current through Register Vol. 24, No. 4, October 1, 2020
Section 6F.85 - Temporary Traffic Barriers
Support:01 Temporary traffic barriers, including shifting portable or movable barriers, are devices designed to help prevent penetration by vehicles while minimizing injuries to vehicle occupants, and to protect workers, bicyclists, and pedestrians.02 The four primary functions of temporary traffic barriers are: A. To keep vehicular traffic from entering work areas, such as excavations or material storage sites;B. To separate workers, bicyclists, and pedestrians from motor vehicle traffic;C. To separate opposing directions of vehicular traffic; andD. To separate vehicular traffic, bicyclists, and pedestrians from the work area such as false work for bridges and other exposed objects.
Option:03 Temporary traffic barriers may be used to separate two-way vehicular traffic.
Guidance:04 (DE Revision) Paragraph deleted.
Standard:05 Temporary traffic barriers shall be supplemented with standard delineation, pavement markings, or channelizing devices for improved daytime and nighttime visibility if they are used to channelize vehicular traffic. The delineation color shall match the applicable pavement marking color.
Guidance:05A (DE Revision) Prior to installation, temporary Portland cement concrete traffic barrier should be painted white on the side adjacent to traffic. If the temporary Portland cement concrete traffic barrier is in place longer than one year, the temporary Portland cement concrete traffic barrier should be painted white on the side adjacent to traffic once per year until the barrier is no longer needed and removed from the roadway.
Option:05B (DE Revision) Temporary Portland cement concrete traffic barrier manufactured with white cement may be used to eliminate the need for painting the temporary Portland cement concrete traffic barrier
Guidance:05C (DE Revision) Temporary traffic barriers should be cleaned once every three months while in place on the roadway unless otherwise directed by DelDOT Traffic. Cleaning of the temporary traffic barrier during winter months should be completed in a manner that does not create ice on the roadway.
Standard:05D (DE Revision) For enhanced conspicuity, non-directional retroreflective panels (see Figure 6F-8) shall be 6-inch wide and 12-inch high with rounded corners. The non-directional retroreflective panel shall have fluorescent orange, prismatic retroreflective sheeting on both sides.05E (DE Revision) When used, non-directional retroreflective panels shall be placed at 50-foot intervals. The first panel shall be mounted within 10 feet of the leading edge of barrier.05F (DE Revision) The non-directional retroreflective panels shall be attached to the temporary traffic barrier in such a manner as to prevent accidental removal. Bolts or epoxy-based adhesives shall be used. 06 Temporary traffic barriers, including their end treatments, shall be crashworthy. In order to mitigate the effect of striking the upstream end of a temporary traffic barrier, the end shall be installed in accordance with AASHTO's "Roadside Design Guide" (see Section 1A.11 ) by flaring until the end is outside the acceptable clear zone or by providing crashworthy end treatments. 06A (DE Revision) Beginning January 1, 2016, temporary Portland cement concrete traffic barrier shall be crashworthy in accordance with NCHRP 350 or latest edition of the Manual for Assessing Safety Hardware (MASH), published by AASHTO.
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Option:06B (DE Revision) Prior to January 1, 2016, temporary Portland Cement concrete traffic barrier that is not crashworthy in accordance with NCHRP 350 or the latest edition of MASH may be used on state maintained roadways if it meets or exceeds all of the following criteria: A. The barrier was manufactured prior to October 1, 2002B. The barrier is constructed of Class A concrete (as defined in the DelDOT Standard Specifications) and is adequately reinforcedC. Has a joint system that provides a positive connection between adjacent segments that can transfer tension and moment in a vertical plane across the joint.
Standard:06C (DE Revision) If temporary Portland Cement concrete traffic barrier that is not crashworthy as described in Paragraph 6A is used, the Contractor shall certify, in writing, to the Engineer and DelDOT Traffic prior to installation, that the barrier meets the above three conditions in Paragraph 6C and the joint system provided has been tested and found acceptable under NCHRP Report 230 test criteria.06D (DE Revision) Temporary traffic barrier shall be offset a minimum of 1 foot from the edge of traveled way.
Guidance:06E (DE Revision) On state-maintained roads with a posted or 85th percentile speed greater than 40 mph, the rate of taper for the flare of a traffic barrier should be 17:1. If space constraints limit the length of flare, a minimum taper rate of 11:1 should be used.06F (DE Revision) When space permits, the leading edge of the attenuator/barrier should have a lateral offset of at least 12 feet from the traveled way.06G (DE Revision) If unpinned barrier is used, a lateral offset of at least 5 feet should be provided between the barrier and the work area. Consideration should be given to pinning the barrier if work is performed within 5 feet of the barrier.06H (DE Revision) When space permits, channelizing devices should be placed along the tangent section of the traveled way for a distance equal to the buffer space measured from the intersection of the barrier and the right-hand edge of the closed travel lane (see Figure 6H-34).
Option:07 Warning lights or steady-burn lamps may be mounted on temporary traffic barrier installations.
Support:08 Movable barriers are capable of being repositioned laterally using a transfer vehicle that travels along the barrier. Movable barriers enable short-term closures to be installed and removed on long-term projects. Providing a barrier-protected work space for short-term closures and providing unbalanced flow to accommodate changes in the direction of peak-period traffic flows are two of the advantages of using movable barriers.09 Figure 6H-45 shows a temporary reversible lane using movable barriers. The notable feature of the movable barrier is that in both Phase A and Phase B, the lanes used by opposing traffic are separated by a barrier.10 Figure 6H-34 shows an exterior lane closure using a temporary traffic barrier. Notes 7 though 9 address the option of using a movable barrier. By using a movable barrier, the barrier can be positioned to close the lane during the off-peak periods and can be relocated to open the lane during peak periods to accommodate peak traffic flows. With one pass of the transfer vehicle, the barrier can be moved out of the lane and onto the shoulder. Furthermore, if so desired, with a second pass of the transfer vehicle, the barrier could be moved to the roadside beyond the shoulder.11 (DE Revision) More specific information on the use of temporary traffic barriers is contained in Chapters 8 and 9 of AASHTO's "Roadside Design Guide" (see Section 1A.11 ) and DelDOT's Design Guidance Memorandum No. 1-21.
2 Del. Admin. Code § 6F.85