A Design Method for the Roadside Clear Zone Based on Accident Simulation Analysis

Table 4

Estimate of the parameters.

Variable	Parameter	Standard deviation	Wald	Degree of freedom	Significance
Departure speed	0.078	0.003	1,877	1	<0.01
Horizontal curve radius	−2.7e − 04	0.001	1,749	1	<0.01
Adhesion coefficient	−4.011	0.186	466	1	<0.01
Shoulder width	−1.515	0.073	434	1	<0.01
Constant	−4.085	0.211	373	1	<0.01