[1] Delft Univ Technol, Dept Transport & Planning, POB 5048, NL-2600 GA Delft, Netherlands
[2] KTH Royal Inst Technol, Dept Transport Sci, Teknikringen 10, S-11428 Stockholm, Sweden
[3] Univ Stuttgart, Dept Transport Planning & Traff Engn, Pfaffenwaldring 7, D-70569 Stuttgart, Germany