Prioritizing Roads Safety Based on the Quasi-Induced Exposure Method and Utilization of the Analytical Hierarchy Process

Document Type: Research Papers


1 MSc., Faculty of Civil Engineering, Iran University of Science and Technology, Tehran, Iran.

2 MSc., Faculty of Civil Engineering, University Putra, Malaysia.

3 Professor, Faculty of Civil Engineering, Iran University of Science and Technology, Tehran, Iran.


Safety analysis of the roads through the accident rates which is one of the widely used tools has been resulted from the direct exposure method which is based on the ratio of the vehicle-kilometers traveled and vehicle-travel time. However, due to some fundamental flaws in its theories and difficulties in gaining access to the data required such as traffic volume, distance and duration of the trip, and various problems in determining the exposure in a specific time, place, and individual categories, there is a need for an algorithm for prioritizing the road safety so that with a new exposure method, the problems of the previous approaches would be resolved. In this way, an efficient application may lead to have more realistic comparisons and the new method would be applicable to a wider range of time, place, and individual categories. Therefore, an algorithm was introduced to prioritize the safety of roads using the quasi-induced exposure method and utilizing the analytical hierarchy process. For this research, 11 provinces of Iran were chosen as case study locations. A rural accidents database was created for these provinces, the validity of quasi-induced exposure method for Iran’s accidents database was explored, and the involvement ratio for different characteristics of the drivers and the vehicles was measured. Results showed that the quasi-induced exposure method was valid in determining the real exposure in the provinces under study. Results also showed a significant difference in the prioritization based on the new and traditional approaches. This difference mostly would stem from the perspective of the quasi-induced exposure method in determining the exposure, opinion of experts, and the quantity of accidents data. Overall, the results for this research showed that prioritization based on the new approach is more comprehensive and reliable compared to the prioritization in the traditional approach which is dependent on various parameters including the driver-vehicle characteristics.


Aldridge, B.H., Himmler, M., Aultman-Hall, L. and Stamatiadis, N. (1999). "Impact of passengers on young driver safety", Transportation Research Record, 1693, 25-30.

Carlson, W.L. (1970). "Induced exposure revisited", HIT Lab Report, University of Michigan, Ann Arbor.

Carr, B.R. (1969). "A statistical analysis on rural Ontario traffic accidents using induced exposure data", Accident Analysis and Prevention, 1(4), 343-358.

Cerrelli, E.C. (1973). "Driver exposure - the indirect approach for obtaining relative measures", Accident Analysis and Prevention, 5(2), 147-156.

Chandraratna, S. and Stamatiadis, N. (2009). "Quasi-induced exposure method, Evaluation of not-at-fault assumption", Accident Analysis and Prevention, 41(2), 308–313.

Chandraratna, S. and Stamatiadis, N. (2003). "Problem driving maneuvers of older drivers", Presented in the 2003 Transportation Research Board Meeting, Washington, D.C.

David, J., DeYong, R.C. and Helander, C.J. (1997). "Estimating the exposure and fatal crash rates of suspended/revoked and unlicensed drivers in California", Accident Analysis and Prevention, 29(1), 17-23.

Hall, W.K. (1970). "An empirical analysis of accident data using induced exposure", HIT Lab Report, University of Michigan, Ann Arbor.

Hing, J.Y. Stamatiadis, N. and Aultman-Hall L. (2003). "Evaluating the impact of passengers on the safety of older drivers", Journal of Safety Research, 34(4), 343-351.

Huang, H. and Chor Chin, H. (2009). "Disaggregate propensity study on red light running crashes using quasi-induced exposure method", Journal of Transportation Engineering, 135(3), 104-111.

Jiang, X. and Lyles, R.W. (2010). "A review of the validity of the underlying assumptions of quasi-induced exposure", Accident Analysis and Prevention, 42(4), 1352-1358.

Jiang, X. and Lyles, R.W. (2007). "Difficulties with quasi-induced exposure when speed varies systematically by vehicle type", Accident Analysis and Prevention, 39(2), 649–656.

Jiang, X. (2005). "Measuring the effectiveness of Michigan graduated driver licensing with quasi-induced exposure", Presented at the 84th Transportation Research Board Annual Meeting, (TRB), Washington DC., January.

Joksch, H.C. (1973). "A pilot study of observed and induced exposure to traffic accident", Accident Analysis and Prevention, 5(2), 127-136.

Kirk, A. and Stamatiadis, N. (200la). "Crash rates and traffic maneuvers of younger drivers", Transportation Research Record, 1779, 68-74.

Kirk, A. and Stamatiadis, N. (200lb). "Evaluation of quasi-induced exposure", Final Report, College of Engineering, University of Kentucky.

Lighthizer, D.R. (1989). "An empirical validation of quasi-induced exposure", Ph.D Dissertation, Department of Civil and Environmental Engineering, Michigan state University, E. Lansing, MI.

Lyles, R.W. (1994). "Quasi-induced exposure: to use or not to use?", Presented at the 94th Transportation Research Board Annual Meeting, January, Washington DC.

Lyles, R.W., Stamatiadis, P. and Lighthizer, D.R. (1991). "Quasi-induced exposure revisited", Accident Analysis and Prevention, 23(4), 275-285.

Rezaei, S. (2011). "Exposure, induced exposure and quasi induced exposure in determining the rate of accidents and road safety measure by using epidemiological methods", M.Sc. Thesis, Department of Civil Engineering, Iran University of Science and Technology.

Saaty, T.L. (2012). "Decision making for leaders: the analytic hierarchy process for decisions in a complex world", Third Edition, RWS publications, Pittsburgh.

Stamatiadis, N. and Puccini, G. (1998). "Fatal crash rates in the south eastern united states - why are they higher?", Transportation Research Record, 1665(1), 118-124.

Stamatiadis, N. and Deacon, J.A. (1997). "Quasi-induced exposure: Methodology and insight", Accident Analysis and Prevention, 29(1), 37–52.

Xu, Z. (2000). "On consistency of the weighted geometric mean complex judgement matrix in AHP1", European Journal of Operational Research, 126(3), 683-687.