Analysis of Severe Injury Accident Rates on Interstate Highways Using a Random Parameter Tobit Model

Table 3

Marginal effect and elasticity values of fixed and random parameters Tobit model.

	Fixed parameter		Random parameter
	Marginal effect	Elasticity	Marginal effect	Elasticity
Logarithm of segment length
Logarithm of annual average daily traffic volume
Number of lanes per direction
Left shoulder width
Right shoulder width
Number of horizontal curves
Number of vertical curves