Modeling Geometric Design Consistency and Road Safety for Two-Lane Rural Highways in the West Bank, Palestine

This study investigates the effect of geometric design consistency on road safety in the West Bank. Studies have shown that operating speed, vehicle stability, alignment indices, and driver’s workload are the common consistency measures that might affect safety. A total of 118-km two-lane rural highways in the West Bank, Palestine, were studied based on limitations of available data. Comprehensive geometric and operating data for the selected highways obtained from field survey, maps, and official sources were used to investigate the effect of design consistency measures on road safety. Crashes for years 2008–2012, totaling 263, were used for model development using the generalized linear regression approach. Tested models were statistically significant at 95%, and adopted models showed acceptable levels of goodness of fit. The recommended model performed well across additional highway sections, additional years of data, validation of algorithm, and “%error” with a high linear correlation. The study adds to the evidence that several geometric design consistency measures contribute to roadway safety. The significant measures for the two-lane rural highways in the West Bank were segment length, traffic volume, difference between operating and design speeds, absolute difference in the 85th percentile speeds between successive design elements, and the ratio of individual curve radius to the average radius. The practical implication of this study, in addition to being able to predict crashes based on the recommended measures, highway designers should pay careful attention to inconsistent designs of two-lane rural highways to reduce their crash frequency.

[1]  Ruediger Lamm,et al.  Highway Design and Traffic Safety Engineering Handbook , 1999 .

[2]  M. Castro,et al.  Spatial analysis of geometric design consistency and road sight distance , 2015, Int. J. Geogr. Inf. Sci..

[3]  Mitsuru Saito.  Review of How to Make Two-Lane Rural Roads Safer: Scientific Background and Guide for Practical Application by R. Lamm, A. Beck, T. Ruscher, T. Mailaender, S. Cafiso, and G. La Cava , 2007 .

[4]  Tarek Sayed,et al.  Traffic accident modeling: some statistical issues , 2006 .

[5]  Khaled Al-Sahili,et al.  Effectiveness of Consistency Measures in Crash Prediction Models for Two-Lane Highways in Palestine , 2018 .

[6]  Massimo Aria,et al.  Continuous Speed Profiles to Investigate Drivers' Behavior on Two-Lane Rural Highways , 2015 .

[7]  Alfredo García,et al.  New Consistency Model Based on Inertial Operating Speed Profiles for Road Safety Evaluation , 2018 .

[8]  Michael H. Kutner.  Applied Linear Statistical Models , 1974 .

[9]  Said M. Easa.  Distributing Superelevation to Maximize Highway Design Consistency , 2003 .

[10]  Shaw-Pin Miaou,et al.  Pitfalls of Using R2 to Evaluate Goodness of Fit of Accident Prediction Models , 1996 .

[11]  Guohui Zhang,et al.  Performance Level of Road Geometric Design Based on Motorcycle – Cars Linear Speed Profile , 2017 .

[12]  Tarek Sayed,et al.  Effect of geometric design consistency on road safety , 2004 .

[13]  C M Poe,et al.  Analyzing Influence of Geometric Design on Operating Speeds Along Low-Speed Urban Streets: Mixed-Model Approach , 2000 .

[14]  K. M. Bauer,et al.  Relationship to Safety of Geometric Design Consistency Measures for Rural Two-Lane Highways , 1999 .

[15]  Patrick T McCoy,et al.  ESTIMATION OF SAFETY AT TWO-WAY STOP-CONTROLLED INTERSECTIONS ON RURAL HIGHWAYS , 1993 .

[16]  Tarek Sayed,et al.  Accident Prediction Models for Urban Unsignalized Intersections in British Columbia , 1999 .

[17]  Tarek Sayed,et al.  Establishing Practical Approach for Design Consistency Evaluation , 2001 .

[18]  Muna Awatta.  Highway design consistency and safety: individual and overall evaluation criteria , 2004 .

[19]  Maria Castro,et al.  Highway Geometric Design Consistency: Speed Models and Local or Global Assessment , 2016 .

[20]  Ruediger Lamm,et al.  A PRACTICAL SAFETY APPROACH TO HIGHWAY GEOMETRIC DESIGN INTERNATIONAL CASE STUDIES: GERMANY, GREECE, LEBANON, AND THE UNITED STATES , 1998 .

[21]  Tarek Sayed,et al.  Using Macrolevel Collision Prediction Models in Road Safety Planning Applications , 2006 .

[22]  Simon Washington,et al.  Validation of FHWA Crash Models for Rural Intersections: Lessons Learned , 2003 .