Dynamic Message Signs

Dynamic Message Signs

Dynamic Message Signs (DMS) are overhead electronic boards that display real-time information to drivers in the greater St. Louis metropolitan area.

They inform drivers about travel times, road closures, crashes, congestion, work zones, traffic signal outages, amber alerts, and weather warnings. There are more than 150 DMS on the interstates and state routes in the region.

The purpose of DMS is to help drivers make informed decisions based on the traffic conditions ahead of them. If lanes are blocked or experiencing heavy congestion, drivers may choose alternate routes to reach their destinations.

DMS are the last chance to communicate with drivers about roadway incidents and work zones that may affect their travel. Since using a smart phone while driving is not safe, DMS provide quick and concise information about the traffic ahead to allow drivers to plan their routes accordingly -- reducing congestion and travel time.

MoDOT collaborates with IDOT, who is a partner in the Gateway Guide program, to coordinate relevant messages on both sides of the river. This ensures that the two states provide the best possible information to drivers who can then make informed decisions. 

Arterial message boards

MoDOT has smaller versions of the Dynamic Message Signs on high-volume major state roads.  These type of message boards can be found on some of the following roads:

  • between Route 367 in North County and Lemay Ferry Road in South County
  • Route 370
  • Route 364

These signs will work in conjunction with speed sensors and traffic cameras to help provide information on travel times, upcoming lane or roadway closures, crashes, and congestion.

These digital boards are placed alongside the roadway, on state property. They are in advance of major cross streets, with enough distance for drivers to make a decision on their routes.  MoDOT makes sure people can see the signs easily and makes sure that the signs will not significantly impact adjacent property owners.

These signs have a very narrow viewing angle, which should prevent light spilling over onto the property of adjacent properties.  They also have a solar sensor which dims the light during nighttime hours.