BEHAVIOUR OF SUV AND MPV-TYPE VEHICLES IN COLLISIONS WITH ROADSIDE SAFETY BARRIERS

摘要

Roadside safety barriers are designed to deflect errant vehicles back onto the carriageway, preventing them from encountering potentially dangerous off-road hazards or crossing into the opposing carriageway on dual carriageways. However, there are concerns that SUVs and MPVs, by virtue of their greater mass and height, may not be well catered for by the current design of safety barrier, which is tested to withstand an impact with a 1500 kg standard car. An analysis of National accident statistics (all police-reported injury accidents in Great Britain) is presented, which indicates that the occupants of these larger vehicles generally incur less severe injuries than occupants of standard cars. Only a small proportion of road accidents involve barrier strikes, and the involvement of a barrier is associated with increased likelihood of rollover and increased injury severity for occupants of all vehicle types. These increases in rollover incidence and injury severity are found to affect SUVs and MPVs much more than standard cars (rollover incidence rises by factors of 4 for cars, 7 for SUVs and 9 for MPVs). However, detailed information on a small number of barrier strike accidents involving SUVs or MPVs taken from TRL's in-depth accident databases (10 cases in total) indicates that the barriers themselves may not be to blame. The barriers are found to exceed their design specification in a number of cases, and the cause of the accident is found in several cases to be difficulty in controlling these larger vehicles in extreme situations. Despite the limitations of a lack of detail in the national accident statistics and a small number of cases for in-depth analysis, this study nevertheless offers a useful insight into an accident scenario in which SUVs and MPVs become less safe for their own occupants than standard cars.