asked the Secretary of State for Transport what efforts have been made to ensure that the design and performance of central reserve safety fences are satisfactory; and if he will make a statement.
Current designs of safety fences were established from extensive research, including full-scale impact testing. Designs are required to contain a 1·5 tonne vehicle travelling at 70 mph and striking the fence at an angle of 20 deg and to redirect it safely, ideally keeping the forces experienced by vehicle occupants as low as possible. Such designs cope most effectively with impacts from cars, the most likely vehicles to collide with safety fences.The Department has a continuing programme of research that may lead to new designs in the future that can cope with a wider range of vehicles at justifiable cost. Recent results from one element of our research programme demonstrated the effectiveness of safety fences in reducing the severity of accidents, and showed that more central reserve safety fences would be justified on dual carriageway roads.Consequently, changes to the Department's standard for safety fences were announced on 17 December 1986 that will substantially increase the level of their provision on dual carriageway trunk roads. They will now be provided on all new roads and gradually on the vast majority of existing roads. We estimate that this will lead to a saving of over 1,000 casualties per annum. I am also writing to my hon. Friend.