HOW DOES THE EDGE HEIGHT OF CURB RAMPS OBSTRUCT BICYCLES?

The aim of this study is to recommend revisions, based on empirical data, to the current curb ramp standards for keeping bicyclists safe. Four types of curb ramps were tested: (1) concrete with a 50 mm edge height, (2) concrete reinforced by a metal plate with a 50 mm edge height, (3) plastic with a 20 mm edge height, and (4) recycled rubber with a 10 mm edge height. Twenty subjects aged 20uu60 years ascended the curbs on a bicycle under various conditions. The angles of approach were 15°, 30°, 45°, 60°, 75° and 90°. Experiments were executed under both wet and dry conditions. We found that when approaching from an angle of 45° or more, all subjects could ascend all ramps under both conditions. From a 15° approach under wet conditions, no subjects ascended the concrete ramps. Some could not ascend at a 15° approach on the concrete ramps in dry conditions, and some could not ascend from a 30° approach on the reinforced concrete ramp in wet conditions. Bicyclists riding on roadways cannot easily ascend a curb ramp with a 50 mm edge, even in dry conditions. We thus recommend that curb ramp edge heights be lower than 50 mm.