State-level accident rates of surface freight transportation : a reexamination.

State-level accident rates for truck, rail, and barge transportation have been updated for mid-1990s shipping conditions. The updated accident, fatality, and injury rates reflect multiyear data for interstate-registered highway carriers, American Association of Railroads member carriers (i.e., all Class 1 and Class 2 railroads), and coastal and internal waterway barge traffic. Adjustments have been made to account for the share of highway combination-truck traffic actually attributable to interstate-registered carriers and for duplicated or otherwise inaccurate or unusable entries in the public-use accident data files applied. State-to-state variation in rates, reflecting recent developments in freight flows, the possible effect of speed limit changes on highway rates, and the stability of rates over time, are discussed. Carrier-specific information was used to confirm the general accuracy of the computed rates for highway shipments. Study conclusions suggest that these rates may be used for the next several years. However, further investigation is suggested, within two to three years, to verify or reject the emergence of a trend toward higher truck accident rates in states that raised highway speed limits between 1995 and 1996.