1. Road Accident Modelling for Highway Development and Management in Developing Countries

December 2004 to August 2005
(i) Indian Institute of Technology, Madras (R,C)
(ii) Transport Research Laboratory, United Kingdom (S)


Scope and Objectives

• To improve transport safety and to reduce impact of accidents on people in rural and urban areas.

• To provide reliable predictors of road accidents for highway development models used in the planning of new and upgraded roads.

• To provide a new road safety component in the HDM-4 model.

The project aims at modeling road accidents as a function of exposure and roadway characteristics. 500 km road length has been selected for the study, which includes National Highways, State Highways, Major and Other District Roads and Hill Roads in urban and rural locations. Kilometer wise accident data on the selected road stretches, for the past three years, has been collected from police records. Other data including traffic volume, width of pavement/shoulder, condition of pavement/shoulder, condition of signs/markings, sight distance at curves, roadside friction due to pedestrian activity, type and proximity of off-shoulder hazards and number of public/private accesses have been collected through field surveys. As the data includes variables of both quantitative and subjective nature, accident frequency is being modeled using Generalised Linear Modelling (GLM) technique.
• Empirical road accident prediction model developed by analyzing the data statistically, using Generalised Linear Modelling (GLM) technique, can be used to predict accidents scientifically.

• The road accident prediction model developed was statistically tested and validated.

• The road accident prediction model gives the expected number of accidents based on classified vehicular traffic, number of accesses to the road, condition of the road and prevailing cross-sectional hazards.

• Increase in number of fast moving vehicles like cars, buses and small trucks causes increase in expected number of road accidents.

• Presence of public and private access causes increase in road accident probability, with public access having a higher impact on accident occurrence.

• The varying conditions of carriageway/shoulder and varying levels of cross-sectional hazards have varying impact on accident probability of the road.

• The road accident prediction model can be used by transportation engineers in evaluating alternate highway designs, duly considering the accident potential due to various elements.
Significant/Utilisation Potential
The final model will provide a new road safety component in the HDM-4 model.
1. Lt. Col. Balachandran, G. (2005), ‘Road Accident Modelling for Two Lane Undivided Rural Highways Under Mixed Traffic Flow Conditions’, M. Tech. theis report (unpublished), Indian Institute of Technology Madras, Chennai.

2. Lt. Col. Balachandran, G., Dinu, R. R., Srinivas, C.,and Dr. Veeraragavan, A., “Road Accident Modelling For High-Speed Highways Under Mixed Traffic Flow Conditions”, Proceedings of Seminar on High Speed Corridor Projects, Indian Roads Congress, New Delhi, 23rd – 24th September, 2005.