01126709

Component

https://doi.org/10.3141/2092-06

http://scholar.google.com...+You&publication_year=2009

Collision prediction models for three-dimensional (3-D) alignments of two-lane rural highways are lacking in the literature. This paper presents such models with vehicle collision data on 5,760 km (3,600 mi) of two-lane rural highways in Washington State collected from 2002 through 2005. Five statistical models were developed for different combinations of 3-D alignments to establish the relationship between collision frequency and the relevant variables. The alignment combinations are (a) horizontal curves combined with crest vertical curves, (b) horizontal curves combined with sag vertical curves, (c) horizontal curves combined with multiple vertical curves, (d) horizontal curves combined with grades of less than 5%, and (e) horizontal curves combined with grades of more than 5%. For each combination, four different statistical techniques were explored: Poisson, negative binomial, zero-inflated Poisson, and zero-inflated negative binomial. For validation, two models were selected and estimated by using the first 3 years of collision data and validated with the last-year data. The results show that the most significant predictors for collisions on horizontal curves on 3-D alignments are the degree of curvature, roadway width (lanes plus shoulders), access density, product of grade value and grade length, road section length, and average annual daily traffic. The results of this study should be useful in evaluating road safety on 3-D alignments and optimizing their design based on the substantive safety approaches.

01137568

09-3514

English

pp 48-56

2009

Transportation Research Record: Journal of the Transportation Research Board

9780309126106

Print

Figures (2) ; References (34) ; Tables (3)

Crashes; Highway curves; Highway safety; Mathematical models; Rural highways; Two lane highways

Crash prediction models; Horizontal curvature; Three dimensional alignments

Washington (State)

Design; Highways; Safety and Human Factors; I20: Design and Planning of Transport Infrastructure; I82: Accidents and Transport Infrastructure

TRIS, TRB, ATRI

Jan 30 2009 7:56PM

• Desirable Spiral Length Based on Driver Steering Behavior
• Effects of Grade on the Speed and Travel Time of Vehicles Entering Driveways
• Exploring the Relationship Between Roadway Characteristics and Speed Variation
• Model for Predicting Speed Along Horizontal Curves on Two-Lane Highways
• Prioritizing Access Management Implementation
• Safety Analysis of Interchanges
• Two Low-Cost Safety Concepts for Two-Way, Stop-Controlled Intersections in Rural Areas