Requirements for work or shadow vehicles to have Truck-Mounted Attenuator (TMA)
Michigan does not require the work vehicle to have a TMA. It does not require truck-mounted attenuators (TMAs) or a shadow vehicle to be used when setting up a lane closure. In its TMA guidelines, Michigan DOT does recommend TMA use for this purpose. Traffic Control Suppliers have brought up that using a TMA may be a hindrance more than a benefit. The nature of the work requires quick maneuvering in and out of traffic. A TMA moves slowly and may cause extended exposure to traffic.