Citation

Hall JW, Turner DS, Hall LE. Transp. Res. Rec. 1994; 1468: 54-59.

Copyright

(Copyright © 1994, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Severity indexes, which serve as indicators of the expected injury consequences of a crash, are an integral part of the analysis of proposed roadside safety improvements. Although research since the 1960s has sought to quantify severity indexes for a range of object types and impact conditions, wide variations remain in the values from which analysts may choose when performing cost-effectiveness evaluations. To clarify the current state of the practice in understanding and using severity indexes, a survey of state highway agencies was conducted. Among the 11 primary parameters used in the AASHTO roadside safety analysis model, respondents expressed the least level of confidence in severity indexes; indeed, more than 70% indicated that they encountered problems in selecting and justifying these values. Numerous respondents asserted a need for the validation of the severity indexes used in the model. General support was expressed for the inclusion of more object types and impact conditions in tabulations of severity indexes, although opinions were divided on the merits of providing a range of severity indexes as opposed to specific values. Survey results also supported the need for continued development of the roadside safety method, better documentation of the procedures, user-friendly computer programs, and additional training.

Language: en

Keywords

Accident prevention; Highway accidents; Mathematical models; Risk assessment; Cost effectiveness; Surveys; Improvement; Computer simulation; Computer software; Highway administration; Roadsides