traffic-flow-dynamics.org/traffic-states

The freeway A5 near Frankfurt

Considered Road Sections

www.autobahnatlas.de
Sketch of the considered freeway section

The A5 north of Frankfurt/Main, Germany is one of the most crowded European freeway sections .

Because of the high traffic demand and the good equipment with detectors, this section is perfectly suited for scientific investigations. In this section, externally controlled traffic signs are active.

In recent times, this section has been upgraded to four regular lines in each driving direction. Additionally, the emergency side lanes are temporarily opened to the traffic at rush hours. As a consequence, congestions have been reduced considerably, at present.

The image data base includes an about 30 km long section

  • from road kilometer 465 (junction Friedberg)
  • to kilometer 492 (Intersection "Westkreuz", Frankfurt) .

Shown are data from a period before the upgrade to four regular lanes

  • from April 3, 2001
  • to September 27, 2001.

Detectors

The data of the images of the traffic states (spatiotemporal evolution of the local speed) originate from double-loop inductive detectors. The loops are buried below the road surface as illustrated by the following satellite image.

aerial view of double-loop
	detectors
Double induction loop

The loop detectors count the vehicles passing the respective cross section on a given lane. Because there are two loops per detector, the speed can be obtained as well from the time difference between passing the first and the second loop.

The data are aggregated in situ over one minute and transmitted to the control center. These historic "minute data" are the basis for reconstructing the spatiotemporal traffic situation (see Method).



    Locations of the detectors
Locations of the detectors


   

The locations of the detectors are illustrated, for both driving directions, in this sketch of the freeway section. You can view the section and the detector locations at Google Maps as well. Notice, however, that the present geometry (four regular lanes) is different from that investigated here.



   
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References

  1. Martin Schönhof, Dirk Helbing: Empirical Features of Congested Traffic States and Their Implications for Traffic Modeling, Transportation Science Vol. 41, No. 2, 135-166 (2007). Abstract, Preprint.

  2. Martin Treiber, Arne Kesting, Dirk Helbing: Three-phase traffic theory and two-phase models with a fundamental diagram in the light of empirical stylized facts, Transportation Research Part B: Methodological 44(8-9), 983-1000 (2010). Abstract, Preprint.