907.8 Speed Trailers Deployed by Others
Support. Speed trailers are a useful tool in work zones to help regulate speed reductions, as well as an important tool for law enforcement when they have a speed enforcement campaign in place. The deployment of speed trailers is limited to work zone and speed enforcement campaign purposes.
Standard. When speed trailers are used in work zones, speed trailers can be deployed by MoDOT, a MoDOT contractor or law enforcement. See EPG 616.6.89 Radar Speed Advisory System (RSAS) for guidance for speed trailer deployment in work zones.
Speed trailer deployment for speed enforcement outside of a work zone shall only be performed by law enforcement or MoDOT. When deployed to support speed enforcement campaigns, the deployment shall be limited to:
- Roadways with posted speed limits of 60 mph or less
- Deployed for a maximum of 7 days for any given 5-mile segment of roadway
- Only deployed on the right side of the roadway
- Offset from the edge of the travel lane a minimum of 6 feet.
Speed trailers shall not be deployed during times of pending winter weather events as the risk of vehicle roadway departures increases and these trailers impede MoDOT’s snow fighting efforts.
Speed trailers shall only be used for speed enforcement and shall not be deployed as long term passive reminders to drivers of their speed. Long term vehicle speed feedback sign installations shall be installed permanently on breakaway supports to the right side of the roadway shoulder in accordance with MoDOT’s policies for these types of installations.
MoDOT shall be notified before speed trailers are deployed. Law enforcement shall contact the district with the request to deploy the trailer, which shall include the following information:
- Mile marker / location
- Duration of the deployment
- Purpose of the deployment.
The location selected for the deployment of a speed trailer shall have good shoulders, or sufficiently flat right of way, to properly support the trailer in a stable condition. The speed trailer shall be clearly visible by the motorist for a minimum of 200 feet, shall not be placed on the blind side of crest hills, immediately downstream of horizontal curves, immediately downstream of entrances and on ramps, or placed under bridges or other structures. The speed trailer shall be offset from the travel lane a minimum of 6 feet and have 5 channelizers placed in advance of the trailer in accordance with Figure 907.8.
The speed trailer shall be configured with the Vehicle Speed Feedback Plaque sign mounted below a Speed Limit (R2-1) sign, see Figure 907.8. The integration of red and blue lights on speed trailers is limited to those devices deployed by law enforcement. The use of red and blue lights on speed trailers deployed by MoDOT or a MoDOT contractor is limited to work zones in conformance with MoDOT Standard Specifications for Highway Construction Section 6188.8.131.52.
The District Engineer shall have the authority to deny a speed trailer deployment request, as well as request a deployed speed trailer be removed from the right of way at any time, if engineering judgement determines the trailer is negatively affecting safety or MoDOT’s ability to maintain the roadway. If the speed trailer is not removed within the requested timeframe, the District Engineer is authorized to remove the trailer from the roadway and relocate it to a MoDOT facility.