902.9 Traffic Control Signals for One-Lane, Two-Way Facilities (MUTCD Chapter 4H)
902.9.1 Application of Traffic Control Signals for One-Lane, Two-Way Facilities (MUTCD Section 4H.01)
Support. A traffic control signal at a narrow bridge, tunnel, or roadway section is a special signal that assigns the right of way for vehicles passing over a bridge or through a tunnel or roadway section that is not of sufficient width for two opposing vehicles to pass. Temporary traffic control signals (see EPG 902.5.44 Temporary and Portable Traffic Control Signals and MUTCD Section 6F.84) are the most frequent application of one-lane, two-way facilities.
Guidance. Sight distance across or through the one-lane, two-way facility should be considered as well as the approach speed and sight distance approaching the facility when determining whether traffic control signals should be installed.
Option. At a narrow bridge, tunnel, or roadway section where a traffic control signal is not justified under the conditions of EPG 902.3 Traffic Control Signal Needs Studies, a traffic control signal may be used if gaps in opposing traffic do not permit the flow of traffic through the one-lane section of roadway.
902.9.2 Design of Traffic Control Signals for One-Lane, Two-Way Facilities (MUTCD Section 4H.02)
Standard. The provisions of EPG 902.5 Traffic Control Signal Features shall apply to traffic control signals for one-lane, two-way facilities, except that:
- A. Durations of red clearance intervals shall be adequate to clear the one-lane section of conflicting vehicles.
- B. Adequate means, such as interconnection, shall be provided to prevent conflicting signal indications, such as green and green, at opposite ends of the section.
902.9.3 Operation of Traffic Control Signals for One-Lane, Two-Way Facilities (MUTCD Section 4H.03)
Standard. Traffic control signals at one-lane, two-way facilities shall operate in a manner consistent with traffic requirements.
When in the flashing mode, the signal indications shall flash red.
Guidance. Adequate time should be provided to allow traffic to clear the narrow facility before opposing traffic is allowed to move. Engineering judgment should be used to determine the proper timing for the signal.