Road accidents can happen due to various reasons related to the Driver, Vehicle and the Environment. The underlying reason for a particular accident may be a combination of various factors belonging to the above three. Based on accident analysis in detail, accident causation models can be developed. When hazardous materials (HazMat) are transported, the severity is manifold due to the additional risks due to the chemical involved. Exposure condition, flammability, spread, toxicity, threshold requirement, pressure, chances of explosion and many other specific factors are added along with the severity of a road accident. Causative factors in the road accidents are analysed which may be useful in the development of accident causation model. The contributing factors in road transportation of HazMat in Kerala also discussed, to find out the scope for developing an Accident Causation Model of road transportation of hazardous materials.