The Effects of Traffic Composition on Freeway Crash Frequency by Injury Severity: A Bayesian Multivariate Spatial Modeling Approach

Table 1

Vehicle categorization.

Category	Categorization criteria				Representative vehicle types
	Head height	No. of axes	No. of wheels	Wheelbase
1	<1.3 m	2	2-4	<3.2 m	Passenger car, jeep, taxi-head truck
2	⩾1.3 m	2	4	⩾3.2 m	Minibus, minivan, light truck
3	⩾1.3 m	2	6	⩾3.2 m	Medium bus, large normal bus, medium truck
4	⩾1.3 m	3	6-10	⩾3.2 m	Large luxury bus, large truck, large trailer, 20-foot container vehicle
5	⩾1.3 m	>3	>10	⩾3.2 m	Heavy truck, heavy trailer, 40-foot container vehicle