Truck Mounted Attenuators (TMA) are widely used on New Zealand Level 2 and 3 state highways and on some network roads that carry high-volume high-speed traffic, to provide safe environments for both roadwork crews and road users. They are used for static, semi-static and mobile operations carried out on sealed carriageways.
However, current practice (specified in the 3rd edition of Transit New Zealand Code of Practice for Temporary Traffic Management (CoPTTM June 2004)) has not prevented 39 TMA incidents occurring in the past five years (July 1999 to July 2004), including four fatalities, as well as numerous injuries. Rather than enhancing safety, the VES currently used on TMA have the potential to adversely affect driving, and to create unsafe circumstances by providing drivers with inefficient messages. This high incident rate involving TMA on New Zealand roads prompted the roading industry to form a Working Group (Fulton Hogan, Higgins Group, and Works Infrastructure) in 2004 to investigate driver perception–reaction issues of operating TMA on the road.
Keywords: Truck Mounted Attenuator (TMA), road safety, traffic management, traffic control, traffic systems, CoPTTM, roadwork, advance warning, visual enhancement system, recognition distance, retroreflectivity, strobe, beacon, perception-reaction, incident