1. Traffic Safety Analyst, Transportation Services, Suite 200, 9304 – 41 Ave., Edmonton, AB, Canada T6E 6G8; formerly, Dept. of Civil and Environmental Engineering, Univ. of Waterloo, Waterloo, ON, Canada N2L 3G1 (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Waterloo, Waterloo, ON, Canada N2L 3G1.