The German Autobahn: an ITS test bed for examining dynamic traffic flow phenomena

Traffic conditions were examined along a 30 km section of northbound Autobahn 5 near Frankfurt, Germany using archived inductive loop detector data. Fifteen bottleneck activations were identified and their reproducible features were described. Bottlenecks became active in the vicinity of on-ramps and off-ramps and once a bottleneck became active, its queue discharge flow was reproducible across multiple activations and across multiple days. The analysis tools used in this study were transformed curves of cumulative vehicle count and cumulative time-mean velocity. These cumulative curves provided the resolution necessary to reveal the spatial and temporal aspects of dynamic freeway traffic flow phenomena. With increasing availability of reliable freeway sensor data, it is important to continue the systematic empirical analysis of freeways in different countries with varying geometric configurations. The results of this research would assist with all aspects of traffic flow modeling, operations and control.