Countermeasures to Improve Road Alignment Consistency of Undivided Rural Roads

Authors

  • Francesca Russo Dept of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio, 21, 80125 Naples, Italy
  • Salvatore Antonio Biancardo Dept of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio, 21, 80125 Naples, Italy

DOI:

https://doi.org/10.3846/bjrbe.2017.26

Keywords:

alignment consistency, crash rate, undivided rural road

Abstract

The research aims to assess the relationships between the crash rates and road consistency. Design consistency  assessment is a tool employed by designers to improve road safety. The case study involved a rural two-lane two-way  road in Southern Italy located on a flat terrain without spiral transition curves between tangent segments and circular  curves. Road alignment consistency was examined in two steps: by adopting standards in force in Italy based on the  design speed profile and by plotting operating speed profile to determine the area bounded by the speed profile and the  average weighted speed, and the standard deviation of operating speeds for each geometric segment. Operating speed  prediction model, which returns the 85th percentile of the speed distribution of the only cars under free flow conditions,  right weather conditions, and lighting was adopted. A negative exponential function was performed to predict  the global consistency of a road as a whole. Finally, a model for predicting the crash rate was calibrated, confirming an  increase of design consistency when the crash rates decrease significantly. The consistency model represents a useful tool during the geometric design process or the evaluation process for two-lane rural highways. 

References

Castro, M.; Pardillo-Mayora, J. M.; Jurado, R. 2013. Development of a Local Operating Speed Model for Consistency Analysis Integrating Laser, GPS and GIS for Measuring Vehicles Speed, The Baltic Journal of Road and Bridge Engineering 8(4): 281−288. https://doi.org/10.3846/bjrbe.2013.36

Dell’Acqua, G. 2015. Modeling Driver Behavior by Using the Speed Environment for Two-Lane Rural Roads, Transportation Research Record 2472: 83–90. https://doi.org/10.3141/2472-10

Dell’Acqua, G.; Busiello, M.; Russo, F. 2013. Safety Data Analysis to Evaluate Highway Alignment Consistency, Transportation Research Record 2349: 121–128. https://doi.org/10.3141/2349-14

Dell’Acqua, G.; De Luca, M.; Mauro, R. 2011a. Road Safety Knowledge-Based Decision Support System, Procedia Social and Behavioral Sciences 20: 973–983. https://doi.org/10.1016/j.sbspro.2011.08.106

Dell’Acqua, G.; De Luca, M.; Mauro, R.; Lamberti, R. 2011b. Motorway Speed Management in Southern Italy, Procedia Social and Behavioral Sciences 20: 49–58. https://doi.org/10.1016/j.sbspro.2011.08.010

Discetti, P.; Dell’Acqua, G.; Lamberti, R. 2011. Models of Operating Speeds for Low-Volume Roads, Transportation Research Record 2203: 219–225. https://doi.org/10.3141/2203-27

Hassan, Y.; Sayed, T.; Tabernero, V. 2001. Establishing Practical Approach for Design Consistency Evaluation, Journal of Transportation Engineering 127(4): 295–302. https://doi.org/10.1061/(ASCE)0733-947X(2001)127:4(295)

Lamm, R.; Choueiri, E. M. 1987. Recommendations for Evaluating Horizontal Design Consistency Based on Investigations in the State of New York, Transportation Research Record 1122: 68–78.

Leisch, J. E. 1977. Dynamics of Highway Design for Safety, Trans-portation 6(1977): 71–83. https://doi.org/10.1007/BF00165367

Mattar-Habib, C.; Polus, A.; Farah, H. 2008. Further Evaluation of the Relationship between Enhanced Consistency Model and Safety of Two-Lane Rural Roads in Israel and Germany, European Journal of Transport and Infrastructure Research 8(4): 320–332.

Medina, A. F.; Tarko, A. 2005. Speed Factors on Two-Lane Rural Highways in Free-Flow Conditions, Transportation Research Record 1912: 39–46. https://doi.org/10.3141/1912-05

Morris, C.; Donnell, E. T. 2014. Passenger Car and Truck Operating Speed Models on Multilane Highways with Combinations of Horizontal Curves and Steep Grades, Journal of Transportation Engineering 140(11). https://doi.org/10.1061/(ASCE)TE.1943-5436.0000715

Park, Y. J.; Saccomanno, F. F. 2006. Evaluating Speed Consistency Between Successive Elements of a Two-Lane Rural Highway, Transportation Research Part A: Policy and Practice 40(5): 375–385. https://doi.org/10.1016/j.tra.2005.08.003

Polus, A.; Mattar-Habib, C. 2004. New Consistency Model for Rural Highways and Its Relationship to Safety, Journal of Transportation Engineering 130(3): 286–293. https://doi.org/10.1061/(ASCE)0733-947X(2004)130:3(286)

Russo, F.; Biancardo, S. A.; Busiello, M. 2016. Operating Speed as a Key Factor in Studying the Driver Behavior in a Rural Context, Transport 31(2): 260–270. https://doi.org/10.3846/16484142.2016.1193054

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Published

27.12.2017

How to Cite

Russo, F., & Biancardo, S. A. (2017). Countermeasures to Improve Road Alignment Consistency of Undivided Rural Roads. The Baltic Journal of Road and Bridge Engineering, 12(4), 211–217. https://doi.org/10.3846/bjrbe.2017.26