2 Del. Admin. Code § 4D.11
Current through Register Vol. 28, No. 5, November 1, 2024
Section 4D.11 - Number of Signal Faces on an ApproachStandard:
01 The signal faces for each approach to an intersection or a midblock location shall be provided as follows:A. If a signalized through movement exists on an approach, a minimum of two primary signal faces shall be provided for the through movement. If a signalized through movement does not exist on an approach, a minimum of two primary signal faces shall be provided for the signalized turning movement that is considered to be the major movement from the approach (also see Section 4D.25).B. See Sections 4D.17 through 4D.20 for left-turn (and U-turn to the left) signal faces.C. See Sections 4D.21 through 4D.24 for right-turn (and U-turn to the right) signal faces. Option:
02 Where a movement (or a certain lane or lanes) at the intersection never conflicts with any other signalized vehicular or pedestrian movement, a continuously-displayed single-section GREEN ARROW signal indication may be used to inform road users that the movement is free-flow and does not need to stop. Support:
03 In some circumstances where the through movement never conflicts with any other signalized vehicular or pedestrian movement at the intersection, such as at T-intersections with appropriate geometrics and/or pavement markings and signing, an engineering study might determine that the through movement (or certain lanes of the through movement) can be free-flow and not signalized. Guidance:
04 If two or more left-turn lanes are provided for a separately controlled protected only mode left-turn movement, or if a left-turn movement represents the major movement from an approach, two or more primary left-turn signal faces should be provided.05 If two or more right-turn lanes are provided for a separately controlled right-turn movement, or if a right-turn movement represents the major movement from an approach, two or more primary right-turn signal faces should be provided. Support:
06 Locating primary signal faces overhead on the far side of the intersection has been shown to provide safer operation by reducing intersection entries late in the yellow interval and by reducing red signal violations, as compared to post-mounting signal faces at the roadside or locating signal faces overhead within the intersection on a diagonally-oriented mast arm or span wire. On approaches with two or more lanes for the through movement, one signal face per through lane, centered over each through lane, has also been shown to provide safer operation. Guidance:
07 (DE Revision) If the posted or statutory speed limit or the 85th-percentile speed on an approach to a signalized location is 45 mph or higher, signal faces should be provided as follows for all new or reconstructed signal installations (see Figure 4D-3): A. The minimum number and location of primary (non-supplemental) signal faces for through traffic should be provided in accordance with Table 4D-1.B. If the number of overhead primary signal faces for through traffic is equal to the number of through lanes on an approach, one overhead signal face should be located approximately over the center of each through lane.C. Except for shared left-turn and right-turn signal faces, any primary signal face required by Sections 4D.17 through 4D.25 for an exclusive turn lane should be located overhead approximately over the center of each exclusive turn lane. When two signal faces are used for a single left-turn lane, they should be positioned a minimum of 8 feet apart (see Section 4D.13) from each other, and both signal faces should be positioned within the extension of the lane lines.D. All primary signal faces should be located on the far side of the intersection.E. In addition to the primary signal faces, one or more supplemental pole-mounted or overhead signal faces should be considered to provide added visibility for approaching traffic that is traveling behind large vehicles.F. Paragraph deleted. Guidance:
07A (DE Revision) Backplates should be used to supplement all vehicular signal heads mounted on mast arms and where an engineering study indicates their need to resolve a problem such as where sun glare, bright sky, and/or complex or confusing backgrounds indicate a need for enhanced signal face conspicuity. Support:
07B (DE Revision) Signal backplates with a retroreflective border provide additional conspicuity for signal heads and providing backplates on mast-arm-mounted signal heads does not require additional tethering. Standard:
07C (DE Revision) If backplates are installed, they shall include a two-inch wide yellow retroreflective border.07D (DE Revision) If backplates are installed on span wire, a tether wire shall also be used.Click here to view Image
| Table 4D-1. Recommended Minimum Number of Primary Signal Faces for Through Traffic on Approaches with Posted, Statutory, or 85th-Percentile Speed of 45 mph or Higher |
| Number of Through Lanes on the Approach | Total Number of Primary Through Signal Faces for the Approach* | Minimum Number of Overhead-Mounted Primary Through Signal Faces for the Approach | |
| 1 | 2 | 1 | |
| 2 | 2 | 1 | |
| 3 | 3 | 2** | |
| 4 or more | 4 or more | 3** | |
| NOTES: * A minimum of two through signal faces is always required (see Section 4D.11). These recommended numbers of through signal faces may be exceeded. Also, see cone of vision requirements otherwise indicated in Section 4D.13. ** If practical, all of the recommended number of primary through signal faces should be located overhead. | |
Guidance:
08 This layout of signal faces should also be considered for any major urban or suburban arterial street with four or more lanes and for other approaches with speeds of less than 45 mph.2 Del. Admin. Code § 4D.11
21 DE Reg. 905 (5/1/2018) (Final)