Crash tests to evaluate the design of temporary traffic control devices for increased safety of cyclists at road works

Abstract

In Sweden there is an on-going process to formulate a national standard regulating the design of temporary traffic control devices used on pedestrian and bicycle paths. This paper presents results from simulated single-bicycle crashes with the purpose to create an understanding of how different features of such devices affect the risk of injuries among cyclists. A Hybrid II 50th percentile crash test dummy was placed in the saddle of a bicycle and crash tests, usually at 25 km/h, were performed. Eleven different types of road equipment were included, and different crash angles were applied, in a total of over 50 crash tests. The road equipment represented temporary traffic control devices of various kind commonly used in Sweden, but also some specifically designed for cyclists. The tests were documented with several video cameras at different angles. Slow motion pictures were analyzed with focus on mechanisms during impact and the following motion of the bicycle and the dummy. Observations regarding “body parts” in contact with the road equipment were of particular interest highlighting design features of importance such as height, smoothness of surfaces and energy-absorbing capacity. The tests show that all bicycle crashes into road equipment can cause injuries and thus the use of work zone material on bicycle paths should be avoided, if possible. Safety barriers designated to prevent cyclists from falling into a shaft must be high enough to do so and be anchored and linked together correctly to prevent them from falling and creating dangerous situations. Temporary traffic control devices should be flexible or energy-absorbing to moderate the injury outcome of a potential bicycle crash. Fences should have a fine meshed net construction to prevent bicycle handlebars from getting stuck. All road equipment should be designed without sharp edges as they could cause injuries to cyclists passing or crashing into the equipment.