1. Institute of Applied Mathematics, RWTH Aachen University, 52064 Aachen, Germany.
2. Department of Mathematics, University of Mannheim, 68131 Mannheim, Germany.
3. Institute of Transportation Studies, UC Berkeley, Berkeley, CA 94720 USA; Department Mathematik, Friedrich-Alexander Universität Erlangen-Nürnberg, Cauerstr. 11, 91058 Erlangen, Germany.
4. Competence Unit for Scientific Computing, Friedrich-Alexander Universität Erlangen-Nürnberg, Martensstr. 5a, 91058 Erlangen, Germany.