Selecting route for hazardous materials (Hazmat) transportation by road is a bilateral decision between local government and the carriers,  involving safety,  environmental and economic factors.  Among them,  the quantitative risk assessment is an important method.  However,  there has been no agreement among researchers on the proper model of the associated transport risk and dfferent models to quantify risk in different ways.  In this paper,  the most common Hazmat transport risk models in the literature are reviewed,  which are divided into five classes including traditional risk model and models derived from it,  perceived risk,  conditional risk,  catastrophe avoidance models and modified traditional risk models.  Moreover,  it is discussed in detail on multiple trips multi-accident.  Finall y,  an example used by these models is evaluated,  and the challenging development of risk model is proposed.