EN 1317 Versus NCHRP 350: Nongating Test Level 3 Crash Cushion Versus Redirective 110-km/h Crash Cushion

Most of the crash cushions available on the market are designed according to one of the standards, namely EN 1317, the Compliant Road Restraint Systems list, and NCHRP 350. EN 1317 is the European standard and it is still used to certify new products, whereas NCHRP 350 is the U.S. standard and it was used up to 2010 to certify road safety products and now it has been replaced by the AASHTO Manual for Assessing Safety Hardware (MASH) standard. It is of interest to compare the requirements of the two standards with respect their recommendations about the design of crash cushions. In particular, this paper reports a comparison between the requirements to design a nongating Test Level (TL) 3 crash cushion according to NCHRP 350 and to design a redirective 110-km/h crash cushion according to EN 1317. NCHRP 350 prescribes to test crash cushion with two different kinds of cars: a small car with a mass of 820 kg and a pick-up of 2 tons. These vehicles are both used to certify the crash cushions for three different levels of velocity: 50 km/h (TL1); 70 km/h (TL2); and 100 km/h (TL3). EN 1317 prescribes to run crash tests with three different types of cars: a small car with a weight of 900 kg; a medium car with a weight of 1,300 kg; and a large car with a weight of 1,500 kg. Crash cushions can be tested at four different levels of velocity: 50km/h, 80km/h, 100 km/h, and 110 km/h. The vehicle used in the test at 50 km/h is the smallest one, the small and medium car are used for the levels of velocity 80 and 100 km/h, and the small and the large cars are used for the level of velocity 110 km/h. The NCHRP 350 standards differ from EN 1317 with respect to the capacity of absorbed energy involved in the frontal impact and especially for the lateral impacts. In addition, the limits of the biomechanical parameters of EN 1317 are less than those of the NCHRP 350. NCHRP 350 allows for larger OIVs and larger average occupant decelerations. In all, NCHRP 350 results in stronger and stiffer crash cushions, whereas EN 1317 allows for more-forgiving crash cushions, which may result in the passenger’s severity of injury being reduced health. A way to design a crash cushion that it is compliant to the two standards could be to test the safety device according to EN1317 and then to run two additional crash tests. The first one would be a capacity crash test to fill the gap between the energies of the frontal impact in the two standards. Running a TL3.31 test on an EN 1317 product may be able to show that the system can fill the energy gap. The second one would be a side-impact test that can show that the EN 1317 device is also able to resist at the larger solicitations typical of the NCHRP 350 side impacts. Among the side impact tests in the NCHRP 350, TL3.37 has the highest lateral kinetic energy. If an EN 1317 crash cushion were able to also pass an NCHTRP 350 TL3.37 test, it could also be expected to comply with the requirements of the other side-impact tests specified in NCHRP 350 for terminals and crash cushions (

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Tables;
  • Pagination: pp 96-103
  • Monograph Title: Roadside Safety Design and Devices: International Workshop, March 26, 2015, Melbourne, Australia
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01675976
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Jul 24 2018 2:34PM