Crash Prediction Models for Horizontal Curve Segments on Two-Lane Rural Roads in Thailand

The number of road crashes continues to rise significantly in Thailand. Curve segments on two-lane rural roads are among the most hazardous locations which lead to road crashes and tremendous economic losses; therefore, a detailed examination of its risk is required. This study aims to develop crash prediction models using Safety Performance Functions (SPFs) as a tool to identify the relationship among road alignment, road geometric and traffic conditions, and crash frequency for two-lane rural horizontal curve segments. Relevant data associated with 86,599 curve segments on two-lane rural road networks in Thailand were collected including road alignment data from a GPS vehicle tracking technology, road attribute data from rural road asset databases, and historical crash data from crash reports. Safety Performance Functions (SPFs) for horizontal curve segments were developed, using Poisson regression, negative binomial regression, and calibrated Highway Safety Manual models. The results showed that the most significant parameter affecting crash frequency is lane width, followed by curve length, traffic volume, curve radius, and types of curves (i.e., circular curves, compound curves, reverse curves, and broken-back curves). Comparing among crash prediction models developed, the calibrated Highway Safety Manual SPF outperforms the others in prediction accuracy.

[1]  Juan de Oña,et al.  Injury severity models for motor vehicle accidents: a review , 2013 .

[2]  C Zegeer,et al.  SAFETY EFFECTS OF CROSS-SECTION DESIGN FOR TWO-LANE ROADS - VOLUME II - APPENDIXES - FINAL REPORT , 1987 .

[3]  Craig Lyon,et al.  Guidelines for Identification of Hazardous Highway Curves , 2000 .

[4]  Ghulam H Bham,et al.  Crash Frequency Modeling using Negative Binomial Models: An Application of Generalized Estimating Equation to Longitudinal Data , 2014 .

[5]  D. Lord,et al.  Adjustment for Maximum Likelihood Estimate of Negative Binomial Dispersion Parameter , 2008 .

[6]  Kara M. Kockelman,et al.  A Bayesian Semi-Parametric Model to Estimate Relationships between Crash Counts and Roadway Characteristics , 2010 .

[7]  K A Abbas.  A SYSTEM APPROACH FOR SUSTAINABLE MANAGEMENT OF TRAFFIC SAFETY , 1996 .

[8]  Jian John Lu,et al.  Hit-and-run crashes in urban river-crossing road tunnels. , 2016, Accident; analysis and prevention.

[9]  C Zegeer,et al.  SAFETY EFFECTS OF GEOMETRIC IMPROVEMENTS ON HORIZONTAL CURVES , 1991 .

[10]  Eric T. Donnell,et al.  Safety performance functions for horizontal curves and tangents on two lane, two way rural roads. , 2018, Accident; analysis and prevention.

[11]  Longyu Shi,et al.  A Cask Evaluation Model to Assess Safety in Chinese Rural Roads , 2018, Sustainability.

[12]  E Hauer,et al.  Overdispersion in modelling accidents on road sections and in empirical bayes estimation. , 2001, Accident; analysis and prevention.

[13]  R. Freckleton,et al.  Model averaging, missing data and multiple imputation: a case study for behavioural ecology , 2010, Behavioral Ecology and Sociobiology.

[14]  Asad J. Khattak,et al.  Development of Safety Performance Functions: Incorporating Unobserved Heterogeneity and Functional Form Analysis , 2018 .

[15]  R. R. Hocking.  The analysis and selection of variables in linear regression , 1976 .

[16]  Karin M Bauer,et al.  Safety Effects of Horizontal Curve and Grade Combinations on Rural Two-Lane Highways , 2013 .

[17]  J. Hilbe.  Negative Binomial Regression: Index , 2011 .

[18]  Bruce Ratner.  The correlation coefficient: Its values range between +1/−1, or do they? , 2009 .

[19]  Christopher M. Monsere,et al.  Calibration of Highway Safety Manual Predictive Models for Oregon State Highways , 2011 .

[20]  Fred L. Mannering,et al.  Negative binomial analysis of intersection accident frequencies , 1996 .

[21]  Francesca Russo,et al.  Safety performance functions for crash severity on undivided rural roads. , 2016, Accident; analysis and prevention.

[22]  J. de Oña,et al.  Identifying the Factors That Increase the Probability of an Injury or Fatal Traffic Crash in an Urban Context in Jordan , 2020, Sustainability.

[23]  Robert C. Deen,et al.  EFFECT OF LANE AND SHOULDER WIDTHS ON ACCIDENT REDUCTION ON RURAL, TWO-LANE ROADS , 1981 .

[24]  Ezra Hauer,et al.  The Art of Regression Modeling in Road Safety , 2014 .

[25]  Gerhard Tutz.  Poisson Regression , 2011, International Encyclopedia of Statistical Science.

[26]  Linjun Lu,et al.  Analysis of Accident Severity for Curved Roadways Based on Bayesian Networks , 2019, Sustainability.

[27]  Michael D. Porter,et al.  How the choice of safety performance function affects the identification of important crash prediction variables. , 2016, Accident; analysis and prevention.

[28]  Zongzhi Li,et al.  A Methodology for Integrating Roadway Safety Hardware Management into the Overall Highway Asset Management Program , 2008 .