1. Ulrich Lank Ingenieurbüro, Gertrudisstrasse 18, 5859 Cologne, Germany; Institute of Road and Traffic Engineering Aachen, Rheinisch-Westfaelische Technische Hochschule, Aachen University, Mies-van-der-Rohe-Strasse 1, 52074 Aachen, Germany.
2. Center for Learning and Knowledge Management, Department of Information Management in Mechanical Engineering, Rheinisch-Westfaelische Technische Hochschule, Aachen University, Dennewartstrasse 27, 52074 Aachen, Germany.
3. Department for Work and Cognition Psychology, Rheinisch-Westfaelische Technische Hochschule, Aachen University, Jägerstrasse 17-19, 52074 Aachen, Germany.