Citation

Hauer E. ITE J. 1991; 61(9): 25-31.

Copyright

(Copyright © 1991, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

This is an examination of methods used to acquire facts about safety that will help transportation engineers to determine how the safety of an intersection is affected by its conversion from stop to yield control. The paper is based on the National Cooperative Highway Research Program Report 320 which addresses the issue. The following matters of method are raised: when to use a comparison group and what size it should be; whether the cross-section and before-and-after approaches give comparable results and which is to be preferred; how to jointly use data from different jurisdictions; why significant testing is to be used sparingly; and how to characterize the accuracy of estimates. The article also expresses concern about the societal pressures that influence what is reported to be the result of research.