Traffic Management Effects of Variable Speed Limit System on a German Autobahn Empirical Assessment Before and After System Implementation

作者：Weikl Simone^*; Bogenberger Klaus; Bertini Robert L

来源：Transportation Research Record, 2013, 2380(2380): 48-60.

DOI：10.3141/2380-06

An empirical study of the traffic flow effects of a variable speed limit (VSL) system on a three-lane German autobahn is presented. The study integrated loop detector data and VSL and driver information provided by overhead dynamic message signs along a 16.3-km section of Autobahn A99 near Munich, Germany. Unlike most VSL deployments, the data sources allowed for a with-and-without analysis to reflect traffic flow and driver behavior in the presence and in the absence of the VSL system. In addition to speed, the primary features of interest were the spatial-temporal extent of the queue (congestion), flow changes caused by identified bottlenecks, the distribution of flow across lanes, the percentage of trucks per lane, and the flow homogeneity between lanes. The analysis recorded bottleneck flow reductions that were balanced across all lanes with an active VSL system. With an inactive VSL system, the flow reductions were slightly lower and occurred primarily in the center and shoulder lanes; there was a small flow increase in the median lane. Further examination indicated that the gain in homogeneity and safety with the system in place was at the cost of capacity. Possible reasons that might explain the differences between the scenarios with and without the VSL system had their basis in the ban against passing by trucks, which was in effect when the driver information system was active.

• 出版日期2013