If an errant vehicle leaves the carriageway and crashes into a safety restraint system, the type of system will determine the risks of injury to the occupants. In the case of the concrete barriers, the shape of the barrier has a substantial influence on the risks of injury to the occupants. As interest in using concrete safety barriers is growing, a Dutch project to develop a safety barrier with a new shape for use in the median of a motorway was initiated. This project resulted in the 'STEP barrier': a single slope barrier with a widening at the base. The step at the base is intended to reduce vehicle damage in the case of minor collisions, in comparison with single slope barriers without a step. The Ministry of Transport developed a number of different types of barrier with a 'STEP shape': a concrete slip-form type, a precast concrete type and a steel one. In order to determine the performance of the STEP barrier full-scale tests have been carried out with the concrete slip-form construction according to the prEN 1317-1 and prEN 1317-2 standards. The test level of containment was H2. The test with the car (TB11: 900 kg, 100 km/h and impact angle 20 degrees) was successful. The trajectory of the car was reasonable stable so the risk of roll-over was minimised. The impact severity level was B. The test with the bus (13000 kg) was also successful. The class of the working width was W1 (width <0.6 m). Based on the results obtained so far the Dutch Ministry of Transport decided to use the step-profile for permanent barriers instead of the New Jersey shape. It is expected that more STEP barriers will be used in the Netherlands in future in the median of motorways. (A)
Samenvatting