Toward Demonstrating Predictability of Bottleneck Activation on German Autobahns

Abstract

Traffic conditions were examined along 30 km (18.6 mi) of northbound Autobahn 5 near Frankfurt, Germany, with archived inductive loop detector data recorded at 1-min intervals. With a focus on the spatiotemporal evolution of traffic between freely flowing and queued conditions, it was possible to identify 15 bottleneck activations and to characterize reproducible features related to their formation, discharge, and dissipation. This was done by systematically probing the excess vehicle accumulation (spatial) and travel time (temporal) that arose between measurement locations. Bottlenecks became active in the vicinity of on- and off-ramps. The evolution of a steady shock of low flow, low velocity, and relatively short duration was traced over 16 km (10 mi). Its cause is not known definitively, but some indications of its formation were revealed. Once a bottleneck became active, its measured outflow was reproducible across multiple activations and multiple days. The analysis tools used were transformed curve...