1. Associate, Scott Wilson Ltd, 12 Regan Way, Nottingham NG9 6RZ, U.K.
2. Researcher, Nottingham Transportation Engineering Centre, Univ. of Nottingham, University Park, Nottingham NG7 2RD, U.K.
3. Professor, Nottingham Transportation Engineering Centre, Univ. of Nottingham, University Park, Nottingham NG7 2RD, U.K.