1. Ulrich Lank Ingenieurbüro, Gertrudisstraße 18, 5859 Cologne, Germany; Institute of Road and Traffic Engineering Aachen, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52074 Aachen, Germany.
2. Institute of Road and Traffic Engineering Aachen, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52074 Aachen, Germany.