Current congestion and loss time information in Hessen
Heusch/Boesefeldt integrates ASDA/FOTO into the traffic centre Hessen (VZH)

For some time now the traffic centre Hessen (VZH) has been using the ASDA/FOTO technique for congestion detection and loss time determination in a test run. The loss times determined by this technique are shown on dynamic text displays referred to as dWiSta (dynamische Wegweiser mit integrierten Stauinformationen – dynamic direction signs with integrated congestion information). The times determined not only inform the road user but at the same time form the basis for a traffic related direction signing.

After a very successful test phase together with the Daimler research department Heusch/Boesefeldt has now completely integrated the technique into the traffic control centre of the traffic centre Hessen. Through this integration ASDA/FOTO directly accesses the GeoDyn2 data keeping of the TCC with its digital map base to be able to automatically get all necessary information on the road network and the traffic sensors when the program is started. Changes in the network or in the traffic recording, which in the data keeping of the TCC are regularly adjusted to the current state, are thus noticed by ASDA/FOTO.

ASDA/FOTO profits from the fact that apart from a few global parameter it does not require any further configurations or parametrisation. This way, the traffic centre Hessen can guarantee a stable quality of the information provided by ASDA/FOTO. In the past, extensive configuration and parametrisation efforts made it difficult for traffic engineering algorithms to provide the desired results since an updating of the configuration and the parameters could not be sufficiently accommodated to the changing circumstances. Apart from that, an extensive data maintenance will always be connected with significant expenses on the side of the operator.

The ASDA/FOTO system developed by the Daimler research department on the basis of the “three phase traffic theory” by Boris Kerner carries out a classification into either “free flow”, “synchronised flow” or “wide, moving jam” and identifies the congestion objects on the basis of the collected traffic data. Once a congestion object has been detected, it is temporally and spaciously tracked by ASDA/FOTO until it dissolves again. Results of the calculation include the length of the congestion as well as travel times and loss time caused by the congestion. Fundamental about ASDA/FOTO is the fact that it does not only unerringly detect moving congestions, but also tracks their movement with great accuracy. This works even when the congestion, moving to an undetected area, is no longer registered by the traffic data collection.

A further considerable advantage of ASDA/FOTO is its simplicity with regard to parametrisation und configuration. All that is needed is basically the information on the road network and the position of the traffic sensors.