Dynamic Message Signs

About: Dynamic Message Signs

Dynamic Message Signs

MoDOT uses overhead electronic message boards, called Dynamic Message Signs (or DMS) to provide needed information to interstate drivers on travel times, interstate closures, crashes or significant congestion, and for abduction alerts. More than 100 of these overhead boards sit at selected spots on the interstates in the greater St. Louis metropolitan area.

These signs are intended to give drivers the information they need to make informed decisions based on the traffic levels ahead of them.  If lanes are congestion or closed, drivers may want to take alternate routes to get to their destinations.

MoDOT works closely with IDOT, who partners with us in the Gateway Guide program, to coordinate important messages on both sides of the river. This gives the two states the ability to provide the best information possible 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.  At this point, message boards are on the following roads:

  • Lindbergh Boulevard (Route 61/67) between Route 67 in North County to Lemay Ferry in South County.

  • Route 141 from Olive Boulevard to I-55.

  • Route 94 from Kingshighway in St. Charles County to Route D west of I-64/Route 40.

Dynamic Message Sign
Dynamic Message Sign
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 located in advance of major cross streets, with enough distance for drivers to make a decision on their routes.  MoDOT will make sure people can see the signs easily, and will make 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 will dim the light during nighttime hours.