Institute for Transport Studies

Recommendations for the width of highly frequented bicycle facilities in consideration of the traffic flow quality

  • contact:

    Prof. Dr.-Ing. Peter Vortisch
    Dipl.-Ing. Sebastian Buck
    M.Sc. Verena Zeidler

  • funding:

    Bundesanstalt für Straßenwesen (BAST)

  • Partner:

    Contractor is the Ruhr University Bochum, Institute for Traffic Engineering and Managemnt. The Institute for Transport Studies at KIT is a subcontractor.

  • startdate:


  • enddate:


In recent years, the number of pedelec users as well as the dissemination of pedelecs and (electric) cargo bikes has increased dynamically in many cities. This dynamic affects also the regulatory framework for bicycle infrastructure in Germany. The „Handbuch für die Bemessung von Straßenverkehrsanlagen“ (HBS) defines a method for the assessment of traffic quality on cycle lanes. In order to improve this assessment method, we investigate in this project how bicycle traffic volume and cycling infrastructure characteristics affect the quality of traffic flow. To this end, we collected data on different cycling infrastructure in various German cities. The data collection aimed at obtaining a solid data base about cyclists’ behavior on infrastructure with high bicycle traffic volumes. By identifying interactions between cyclists in the data we quantify negative effects on traffic flow quality. Based on the empirical data, we conduct traffic simulations for determining the levels of service under varying conditions. The simulation also offers the possibility to extrapolate trends like growing numbers of cargo bikes. The simulation results are used for building an analytical model that can expand the current method for assessing traffic flow quality in the HBS. The Institute for Transport Studies is responsible for the traffic simulations.