Evaluation of the Speed Reduction Effects of Automated Speed Enforcements on Freeways

摘要

Automated speed enforcement (ASE) has been considered an effective approach to reduce speeding on freeways. Until recently, however, impacts of ASE on vehicle speeds on freeways are still not clear in China. The primary objective of this study is to evaluate the effectiveness of ASE in reducing vehicle speeds and speeding on freeways. To achieve the research objective, vehicle speed data were measured at three treatment segments and three control groups with a radar gun. Statistical testing was conducted to compare speeds at deployment locations of ASE and those from control locations or control groups. It is found that the spatial extent of speed reduction effectiveness of ASE on cantilevers is about 1.6 km to 2 km, while the spatial extent is about 1 km for ASE by roadside. Both of the two methods shave significant effectiveness in reducing speeds and speeding.