TRB Pubsindex
Text Size:
x

« Prev Next »

Return to Results | New Search

Bookmark and Share

Title:

A Joint Analysis of Secondary Collisions and Injury Severity Levels Using Structural Equation Models

Accession Number:

01588972

Record Type:

Component

Abstract:

This study aims to investigate the contributing factors to secondary collisions and the effects of secondary collisions on injury severity levels. Manhattan, which is the most densely populated urban area of New York City, is used as a case study. In Manhattan, about 7.5% of crash events get involved with secondary collisions and as high as 9.3% of those secondary collisions lead to incapacitating and fatal injuries. Structural equation models (SEMs) are proposed to jointly model the presence of secondary collisions and injury severity levels. This study contributes to the literature by fully exploring the determinants of secondary collisions such as speeding, alcohol, fatigue, brake defective, limited view and rain. To assess the temporal effects, the authors use time as a moderator in the proposed SEM framework and results indicate that it is more likely to sustain secondary collisions and severe injuries at night. The parameter estimates of the proposed SEM are further compared with those of the standard probit models which estimate the presence of secondary collisions and injury severity independently. Results show that standard probit models overestimate the safety effects of confounding variables (i.e. variables that can affect both secondary collision occurrence and injury severity) by mixing the direct and indirect effects. In addition, it is found that the standard probit models significantly overestimate the effects of secondary collisions on injury severity propensity by 127.6% for daytime crashes and by 121.2% for nighttime crashes, since the endogeneity of the presence of secondary collisions is ignored in the estimation. Understanding the causes and impacts of secondary collisions can help the transportation agencies and automobile manufacturers develop effective injury prevention countermeasures.

Supplemental Notes:

This paper was sponsored by TRB committee ANB20 Standing Committee on Safety Data, Analysis and Evaluation.

Monograph Accession #:

01584066

Report/Paper Numbers:

16-0206

Language:

English

Corporate Authors:

Transportation Research Board

500 Fifth Street, NW
Washington, DC 20001 United States

Authors:

Xie, Kun
Ozbay, Kaan
Yang, Hong

Pagination:

18p

Publication Date:

2016

Conference:

Transportation Research Board 95th Annual Meeting

Location: Washington DC, United States
Date: 2016-1-10 to 2016-1-14
Sponsors: Transportation Research Board

Media Type:

Web

Features:

Figures; References (31) ; Tables

Geographic Terms:

Manhattan (New York, New York)

Subject Areas:

Highways; Safety and Human Factors; I84: Personal Injuries

Source Data:

Transportation Research Board Annual Meeting 2016 Paper #16-0206

Files:

TRIS, TRB, ATRI

Created Date:

Jan 12 2016 4:20PM