Investigating the (length) constraints imposed by the Front Underrun Protection Regulation

Transport & Environment contributed to a European Commission expert group considering the appropriate technical requirements if the maximum length of goods vehicles were to be increased to permit safer and more aerodynamic designs. T&E commissioned this report by Apollo Vehicle Safety to assess: the extent to which the Front Underrun Protection Regulation (UNECE R93) constrains the maximum length of cabs; what the implications would be if it needed amendment; and whether alternative regulatory approaches could allow a length increase without amending R93 or compromising safety.

Previous analysis was based on the assumption that a front underrun protection fitted to an extended length vehicle would deflect under test loads by the maximum 400mm permitted by the current rules. This more detailed examination has identified that most of a small sample of production front underrun protections for which data was available was considerably stiffer than the minimum required. Using a front underrun protection of this stiffness would allow an extension in length of 800mm without amending the current rules. However, as those rules were developed for flat fronted truck designs, some sub-optimal conditions remain.