Truck Rear Underrun Dynamic Crash Test in AS/NZS 3845.2:2017 Standard – a World’s First for Heavy Vehicle Crashworthiness

Each year around ten to twelve fatalities occur as a result of truck rear underruns in Australia and New Zealand. The injuries are usually horrific. Any car impact protection devices such as crumple zones, frontal airbags, or pre-tensioning belts are completely negated by an obvious mismatch between truck with an extended rear frame and a car’s crashworthiness systems. Given both Australia and New Zealand have adopted a ‘Safe System Approach’ road safety strategy, all such foreseen fatalities need to be addressed if a design countermeasure can be implemented. Despite the need for a standard having been recognised for some decades, there has been no effective legislation or Australian Design Rule requiring truck rear under run barriers. It was not until this year (2017) that the redrafted AS/NZ 3845.2 standard set out a crash test performance requirement for such barriers. This is the first time anywhere in the world such a dynamic crash test requirement has been specified in any official document agreed to by regulators. Brief details of the crash test matrix, the criteria for a barrier to be compliant with the standard and the basis on which requirements were established for a truck rear underrun protection device (barrier) is presented. A five star ANCAP rated car crashing into AS/NZS 3845.2 compliant truck rear underrun barriers at speeds of up to around 70 km/h are now survivable.