MUTCD M4-12: Emergency Routing Signs and Plaques

The M4-12 sign is covered in Section 2D.59 of the Manual on Uniform Traffic Control Devices, 11th Edition. Below are the provisions from that section that describe when the sign is used and how it is placed.

What it means and when it is used

• Option · Permitted (may)
  EMERGENCY ROUTE (M4-11 and M4-11a) signs and EMERGENCY ROUTE TO (M4-11bP and M4-11cP) plaques mounted on a directional assembly may be permanently installed on conventional roadways to provide trailblazing along a designated diversionary route to bypass a traffic incident.
• Standard · Required (shall)
  Emergency Routing signs and plaques shall only be installed at departure points and along diversion routes for directing road users around highway segments in areas that are more susceptible to traffic incidents (see Figure 2D-38). EMERGENCY ROUTE and EMERGENCY ROUTE TO signs shall be placed at each turning decision point along the designated route until it rejoins the original route or until other directional signs…

Placement and mounting

• Support · Information
  As part of an agency’s transportation incident management plan it is sometimes desirable to permanently sign routes that provide rerouting of traffic around highway segments susceptible to traffic incidents. Permanently- installed Emergency Routing signs and plaques (see Figure 2D-37) provide direction on conventional roads from an exit located upstream of an area that can be susceptible to traffic incidents back to…
• Support · Information
  The purpose of Emergency Routing signs and plaques is for corridor management along routes that have recurring incidents and have reasonable rerouting paths available. These signs are intended to be permanently installed to provide instant rerouting guidance to road users when traffic congestion or backups first begin even before emergency responders could provide temporary traffic control for rerouting traffic.…
• Standard · Required (shall)
  Orange or pink shall not be used as alternate colors on permanently-installed signs or plaques for rerouting traffic during an incident or other event. If a route shield is displayed as part of the message, the wording of the sign or plaque shall be EMERGENCY ROUTE TO as shown in Figure 2D-37.

Where to read the rest

• Full text: MUTCD Section 2D.59: Emergency Routing Signs and Plaques
• Minimum sign sizes by roadway type are in the size section for this chapter: Section 2D.05
• Mounting height, lateral offset and retroreflectivity for any sign: MUTCD sign placement guide

Related signs in Section 2D.59