Delaware Administrative Code
Title 2 - Transportation
2000 - Department of Transportation
2400 - Division of Transportation Solutions
2402 - Manual on Uniform Traffic Control Devices (MUTCD)
Part 4 - Highway Traffic Signals
Chapter 4D - TRAFFIC CONTROL SIGNAL FEATURES
Section 4D.06 - Signal Indications- Design, Illumination, Color, and Shape
Current through Register Vol. 28, No. 3, September 1, 2024
Standard:
01 Each signal indication, except those used for pedestrian signal heads and lane-use control signals, shall be circular or arrow.
02 Letters or numbers (including those associated with countdown displays) shall not be displayed as part of a vehicular signal indication.
03 Strobes shall not be used within or adjacent to any signal indication.
04 Except for the flashing signal indications and the pre-emption confirmation lights that are expressly allowed by the provisions of this Chapter, flashing displays shall not be used within or adjacent to any signal indications.
05 Each circular signal indication shall emit a single color: red, yellow, or green.
06 Each arrow signal indication shall emit a single color: red, yellow, or green except that the alternate display (dual-arrow signal section) of a GREEN ARROW and a YELLOW ARROW signal indication, both pointing in the same direction, shall be permitted, provided that they are not displayed simultaneously.
07 The arrow, which shall show only one direction, shall be the only illuminated part of an arrow signal indication.
08 Arrows shall be pointed:
09 Except as provided in Paragraph 10, the requirements of the publication entitled "Vehicle Traffic Control Signal Heads" (see Section 1A.11) that pertain to the aspects of the signal head design that affect the display of the signal indications shall be met.
Guidance:
10 The intensity and distribution of light from each illuminated signal lens should comply with the publications entitled "Vehicle Traffic Control Signal Heads" and "Traffic Signal Lamps" (see Section 1A.11).
Standard:
11 References to signal lenses in this section shall not be used to limit signal optical units to incandescent lamps within optical assemblies that include lenses.
Support:
12 Research has resulted in signal optical units that are not lenses, such as, but not limited to, light emitting diode (LED) traffic signal modules. Some units are practical for all signal indications, and some are practical for specific types such as visibility-limited signal indications.
Guidance:
13 If a signal indication is so bright that it causes excessive glare during nighttime conditions, some form of automatic dimming should be used to reduce the brilliance of the signal indication.