Analysis of Existing Data: Prospective Views on Methodological Paradigms

A large component of the safety research undertaken in the second Strategic Highway Research Program (SHRP 2) is aimed at reducing the injuries and fatalities that result from highway crashes. Through a naturalistic driving study (NDS) involving more than 3,000 volunteer drivers, SHRP 2 expects to learn more about how individual driver behavior interacts with vehicle and roadway characteristics. In anticipation of the large volume of data to be collected during the NDS, several projects were conducted to demonstrate that it is possible to use existing data from previous naturalistic driving studies and data from other sources to further the understanding of the risk factors associated with road crashes. More specifically, the four S01 projects, entitled Development of Analysis Methods Using Recent Data, examined the statistical relationship between surrogate measures of collisions (conflicts, critical incidents, near collisions, and roadside encroachment) and actual collisions. This report presents the results of one of these projects, undertaken by Pennsylvania State University. It documents the second phase of a two-phase project under SHRP 2 Safety Project S01B.