Distinguishing between Rural and Urban Road Segment Traffic Safety Based on Zero-Inflated Negative Binomial Regression Models

Bin Wang,Cuiping Zhang,Xuedong Yan,Meiwu An

doi:10.1155/2012/789140

Abstract

In this study, the traffic crash rate, total crash frequency, and injury and fatal crash frequency were taken into consideration for distinguishing between rural and urban road segment safety. The GIS-based crash data during four and half years in Pikes Peak Area, US were applied for the analyses. The comparative statistical results show that the crash rates in rural segments are consistently lower than urban segments. Further, the regression results based on Zero-Inflated Negative Binomial (ZINB) regression models indicate that the urban areas have a higher crash risk in terms of both total crash frequency and injury and fatal crash frequency, compared to rural areas. Additionally, it is found that crash frequencies increase as traffic volume and segment length increase, though the higher traffic volume lower the likelihood of severe crash occurrence; compared to 2-lane roads, the 4-lane roads have lower crash frequencies but have a higher probability of severe crash occurrence; and better road facilities with higher free flow speed can benefit from high standard design feature thus resulting in a lower total crash frequency, but they cannot mitigate the severe crash risk.

Highlights

Previous studies have been focused on distinguishing between rural and urban traffic safety using traffic crash data, but the influence of rural or urban settings on segment safety is controversial
It shows that the percentage of segments with higher crash rates within the urban region is more than rural areas
Before reaching the common agreement on the difference between rural and urban traffic safety, it is important to clarify the definition of “rural.” Generally, to distinguish from urban environments, rural areas have the attributes associated with demographic features e.g., low population size and density, outside boundary of urban area, economic statues low economic indicators, farming, and agriculture, social structure e.g., intimate, informal, and homogeneous forms of social interaction, limited social resources, cultural characteristics e.g., traditional, conservative, provincial, slow to change, and so forth

Summary

Introduction

Previous studies have been focused on distinguishing between rural and urban traffic safety using traffic crash data, but the influence of rural or urban settings on segment safety is controversial. The fatal traffic crash research indicated that fatality rates in rural areas are higher than in urban areas 1–3. The higher fatality and injury rates in rural road facilities. Some studies reported that crash frequencies in urban areas were higher than those in rural areas 7, 8 , because urban regions involve more complex traffic conditions, high traffic volume, congestion, poor pavement conditions, and so forth 9. While the risk of severe crashes appears higher in rural segments, no differences were identified in the cause of injury and place of injury between urban and rural drivers 10

Methods

Results

Conclusion