Influence of Calibration Factors on Crash Prediction on Rural Two-Lane Two-Way Roadway Segments
Publication: Journal of Transportation Engineering, Part A: Systems
Volume 145, Issue 6
Abstract
Calibration factors are applied in the Highway Safety Manual predictive method for rural two-lane, two-way roadway segments to adjust the estimate for local conditions. This research aims to evaluate and recommend improvements related to the estimation of these calibration factors. An aggregated and disaggregated analysis was performed to study the influence of different calibration factors on the prediction of the number of crashes in North Carolina. As a result, those calibration factors based on both types of road elements (horizontal curves and tangents) led to overestimating and underestimating the number of crashes on tangents and horizontal curves, respectively. Furthermore, the calibration factors based on fatal and injury crashes allowed a more accurate estimation of the predicted number of crashes than those calibrated considering all severity levels. Therefore, it is recommended to apply different calibration factors for each type of road element and each type of crash severity.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research was subsidized by the Spanish Ministry of Economy, Industry, and Competitiveness through “Ayudas a la movilidad predoctoral para la realización de estancias breves en centros de I+D 2016.” In addition, the authors would like to thank the North Carolina Department of Transportation (NCDOT), which provided traffic and crash data.
References
AASHTO. 2010. Highway safety manual. Washington, DC: AASHTO.
Alluri, P., D. Saha, and A. Gan. 2016. “Minimum sample sizes for estimating reliable Highway Safety Manual (HSM) calibration factors.” J. Transp. Saf. Secur. 8 (1): 56–74. https://doi.org/10.1080/19439962.2014.978963.
Banihashemi, M. 2012. “Sensitivity analysis of data set sizes for highway safety manual calibration factors.” Transp. Res. Rec. 2279: 75–81. https://doi.org/10.3141/2279-09.
Brimley, B. K., M. Saito, and G. G. Schultz. 2012. “Calibration of highway safety manual safety performance function.” Transp. Res. Rec. 2279: 82–89. https://doi.org/10.3141/2279-10.
Camacho-Torregrosa, F. J., A. M. Pérez-Zuriaga, J. M. Campoy-Ungría, A. García, and A. P. Tarko. 2015. “Use of heading direction for recreating the horizontal alignment of an existing road.” Comput.-Aided Civ. Infrastruct. Eng. 30 (4): 282–299. https://doi.org/10.1111/mice.12094.
Findley, D., C. Zegeer, C. Sundstrom, J. Hummer, and W. Rasdorf. 2012. “Applying the highway safety manual to two-lane road curves.” J. Transp. Res. Forum 51 (3): 25–38.
Li, L., V. V. Gayah, and E. T. Donnell. 2017. “Development of regionalized SPFs for two-lane rural roads in Pennsylvania.” Accid. Anal. Prev. 108: 343–353. https://doi.org/10.1016/j.aap.2017.08.035.
Lord, D., P.-F. Kuo, and S. Geedipally Reddy. 2010. “Comparison of application of product of baseline models and accident-modification factors and models with covariates: Predicted mean values and variance.” Transp. Res. Rec. 2147: 113–122. https://doi.org/10.3141/2147-14.
Lu, J., K. Haleem, P. Alluri, A. Gan, and K. Liu. 2014. “Developing local safety performance functions versus calculating calibration factors for SafetyAnalyst applications: A Florida case study.” Saf. Sci. 65: 93–105. https://doi.org/10.1016/j.ssci.2014.01.004.
Lubliner, H. 2011. “Evaluation of the highway safety manual crash prediction model for rural two-lane highway segments in Kansas.” Ph.D. thesis, Civil, Environmental, and Architectural Engineering, Univ. of Kansas.
Mehta, G., and Y. Lou. 2013. “Calibration and development of safety performance functions for Alabama.” Transp. Res. Rec. 2398: 75–82. https://doi.org/10.3141/2398-09.
Michigan DOT. 2012. Michigan calibration values for the highway safety manual. Lansing, MI: Michigan DOT.
Shin, H.-S., S. Dadvar, and Y.-J. Lee. 2015a. “Results and lessons from local calibration process of the highway safety manual for the state of Maryland.” Transp. Res. Rec. 2515: 104–114. https://doi.org/10.3141/2515-14.
Shin, H.-S., J. W. Yu, S. Dadvar, and Y.-J. Lee. 2015b. “Statistical evaluation of different sample sizes for local calibration process in the highway safety manual.” In Proc., Transportation Research Board 94th Annual Meeting. Washington, DC: Transportation Research Board.
Shirazi, M., D. Lord, and S. R. Geedipally. 2016. “Sample-size guidelines for recalibrating crash prediction models: Recommendations for the highway safety manual.” Accid. Anal. Prev. 93: 160–168. https://doi.org/10.1016/j.aap.2016.04.011.
Smith, S., D. Carter, and R. Srinivasan. 2017. Updated and regional calibration factors for highway safety manual crash prediction models. Raleigh, NC: North Carolina DOT.
Srinivasan, R., and D. Carter. 2011. Development of safety performance functions for North Carolina. Raleigh, NC: North Carolina DOT.
Srinivasan, R., M. Colety, G. Bahar, B. Crowther, and M. Farmen. 2016. “Estimation of calibration functions for predicting crashes on rural two-lane roads in Arizona.” Transp. Res. Rec. 2583: 17–24. https://doi.org/10.3141/2583-03.
Srinivasan, S., P. Haas, N. S. Dhakar, R. Hormel, D. Torbic, and H. Douglas. 2011. Development and calibration of highway safety manual equations for florida conditions. Tallahassee, FL: Florida DOT.
Trieu, V., S. Park, and J. McFadden. 2014. “Use of Monte Carlo simulation for a sensitivity analysis of highway safety manual calibration factors.” Transp. Res. Rec. 2435: 1–10. https://doi.org/10.3141/2435-01.
Williamson, M., and H. Zhou. 2012. “Develop calibration factors for crash prediction models for rural two-lane roadways in Illinois.” Procedia-Social Behavioral Sci 43: 330–338. https://doi.org/10.1016/j.sbspro.2012.04.106.
Xie, F., K. Gladhill, K. Dixon, and C. Monsere. 2011. “Calibration of highway safety manual predictive models for Oregon state highways.” Transp. Res. Rec. 2241: 19–28. https://doi.org/10.3141/2241-03.
Yamamoto, T., J. Hashiji, and V. N. Shankar. 2008. “Underreporting in traffic accident data, bias in parameters and the structure of injury severity models.” Accid. Anal. Prev. 40 (4): 1320–1329. https://doi.org/10.1016/j.aap.2007.10.016.
Information & Authors
Information
Published In
Journal of Transportation Engineering, Part A: Systems
Volume 145 • Issue 6 • June 2019
Copyright
©2019 American Society of Civil Engineers.
History
Received: Jan 3, 2018
Accepted: Nov 26, 2018
Published online: Apr 8, 2019
Published in print: Jun 1, 2019
Discussion open until: Sep 8, 2019
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.