The effect of cab style on the accident experience of heavy trucks

Trucks and tractors of two cab styles--Conventional (with the engine forward of the driver compartment) and Cabover (with the engine below the driver compartment) are compared with respect to operational characteristics and occupant injury experience. Accident data from city, state, and federal sources are analyzed; the latter are compared with national exposure information to determine accident, injury, and fatality rates (per mile traveled). There are major differences in usage, including trip length, cargo type, cargo weight, etc. between the two different cab styles. In this study an attempt was made to measure the injury rates after controlling for such usage variations. It is concluded that injury and fatality rates derived from the Bureau of Motor Carrier Safety statistics are not different for the two cab styles, but that fatality rates derived from a combination of the Fatal Accident Reporting System and the Truck Inventory and Use Survey show the occupants of Cabovers to be at a somewhat greater risk.