Enhanced Bus Front End Geometries for Improved Pedestrian Crashworthiness

The influence of the global geometry of bus front ends on pedestrian head and thorax injuries and run-over risks was assessed via computational simulations (LS_DYNA). A concept design, derived from a Design of Experiments (DOE) study, was compared to two existing buses, representing current and previous generation London bus designs. The DOE demonstrated that, when weighted based on London collision data, the risks of head and thorax injuries and run-overs may be minimised by an enhanced bus front end design with a vertical rake angle of 7°, a rake angle transition height of 753 mm and inner and outer horizontal angles of 16° and 24°. When compared to current and previous generation bus front end designs across a range of impact positions, the enhanced bus front end design reduced mean serious (AIS3+) head injury risks by 26-37 percentage points (pp) at 30 mph impact speeds, mean serious (AIS3+) thorax injury risks by 4-5 pp at 20 mph and 30 mph impact speeds and the proportion of run-over events by 20-33 pp at impact speeds <30 mph. This research indicates that substantial casualty saving benefits may be gained with greater consideration given to the global geometry of bus front end designs.