Safety Effects of Shoulder Paving for Rural and Urban Interstate, Multilane, and Two-Lane Highways
Publication: Journal of Transportation Engineering
Volume 139, Issue 10
Abstract
This paper introduces an Empirical Bayesian (EB) before-after analysis method for assessing the effects of highway shoulder paving on safety performance. In the first step, multi-year data on field-observed crash frequencies for highway segments with pavement resurfacing and shoulder paving (Type I treatment) and highway segments with pavement resurfacing only (Type II treatment), as well as untreated highway segments, on the Illinois state–maintained rural and urban interstate, multilane, and two-lane highways are collected. Next, data on untreated highway segments are used to calibrate safety performance functions (SPFs) and to predict crash frequencies for Type I and II treated highway segments, in the cases where respective treatments not been implemented. After computing the EB-adjusted crash frequency as a weighted sum of field-observed and SPF-predicted crash frequencies, the EB crash frequency for the after-treatment period is established by adjusting the EB crash frequency for the before-treatment period according to changes in traffic volumes and segment lengths between before- and after-treatment periods. The safety effects of shoulder paving are determined as the difference in the EB-adjusted Type I and II crash frequencies for the after-treatment period. It is revealed that reductions in shoulder-related fatal, injury, and property damage only (PDO) crashes from shoulder paving varies greatly by highway functional classification; and adding a new paved shoulder tends to be more effective in terms of crash reductions than paving the same width of the existing paved shoulder that has deteriorated over time or widening the paved shoulder.
Get full access to this article
View all available purchase options and get full access to this article.
References
AASHTO. (2010). Highway safety manual, 1st Ed., American Association of State Highway and Transportation Officials, Washington, DC.
Cottrell, B. H. (1993). “Cost analysis of paved shoulders.”, Transportation Research Board, Washington, DC, 73–80.
Federal Highway Administration (FHWA). (2010). “Safety Analyst™: Software tools for safety management of specific highway sites.”, U.S. Department of Transportation, Washington, DC.
Fitzpatrick, K., Schneider, W. H., and Park, E. S. (2005). “Comparisons of crashes on rural two-lane and four-lane highways in Texas.” Texas A&M Univ., College Station, TX.
Greene, W. H. (2008). NLOGIT Version 4.0 user’s manual, Econometric Software, Bellport, NY.
Gross, F., and Jovanis, P. P. (2007). “Estimation of safety effectiveness of changes in shoulder width with case control and cohort methods.”, Transportation Research Board, Washington, DC, 237–245.
Hadi, M. A., Aruldhas, J., Chow, L.-F., and Wattleworth, J. A. (1995). “Estimating safety effects of cross-section design for various highway types using negative binomial regression.”, Transportation Research Board, Washington, DC, 169–177.
Hauer, E. (1997). Observational before-after studies in road safety: Estimating the effect of highway and traffic engineering measures on road safety, Pergamon Press, Elsevier Science, Oxford, U.K.
Hauer, E., and Lovell, J. (1984). “Safety measures aimed at reducing accidents occasioned by vehicles stopped on freeway shoulders.” Dept. of Civil Engineering, Univ. of Toronto, Toronto, Canada.
Jovanis, P. P., and Chang, H. (1985). “Modeling the relationship of crashes to miles traveled.”, Transportation Research Board, Washington, DC, 42–51.
Klop, J. R., and Khattak, A. J. (1999). “Factors influencing bicycle crash severity on two-lane, undivided roadways in North Carolina.”, Transportation Research Board, Washington, DC, 78–85.
Ksaibati, K., and Crowe, I. (1999). “Evaluation of pavement shoulders.” Dept. of Civil and Architectural Engineering, Univ. of Wyoming, Laramie, WY.
Li, Z., Knight, S., Cook, L. J., Hyde, L. K., Holubkov, R., and Olson, L. M. (2008). “Modeling motor vehicle crashes for street racers using zero-inflated models.” Accid. Anal. Prev., 40(2), 835–839.
Long, J. S. (1997). Regression models for categorical and limited dependent variables, Sage, Thousand Oaks, CA.
Lord, D., Washington, S. P., and Ivan, J. N. (2005). “Poisson, Poisson-gamma and zero-inflated regression models of motor vehicle crashes: Balancing statistical fit and theory.” Accid. Anal. Prev., 37(1), 35–46.
Lord, D., Washington, S. P., and Ivan, J. N. (2007). “Further notes on the application of zero-inflated models in highway safety.” Accid. Anal. Prev., 39(1), 53–57.
Malyshkina, N., and Mannering, F. L. (2010). “Zero-state Markov switching count-data models: An empirical assessment.” Accid. Anal. Prev., 42(1), 122–130.
Miaou, S.-P. (1996). “Measuring the goodness-of-fit of accident prediction models.”, Federal Highway Administration, U.S. Department of Transportation, Washington, DC.
Miaou, S.-P., Hu, P. S., Wright, T., Davis, S. C., and Rathi, A. K. (1993). “Development of relationship between truck crashes and geometric design: Phase I.”, Federal Highway Administration, Washington, DC.
McGee, H. W., Hughes, W. E., and Daily, K. (1995). “Effect of highway standards on safety.”, National Cooperative Highway Research Program, Transportation Research Board, National Academies Press, Washington, DC.
Neuman, T. R., et al. (2003). “Guidance for implementation of the AASHTO strategic highway safety plan, Vol. 6: A guide for addressing run-off-road collisions.”, National Cooperative Highway Research Program, Transportation Research Board, National Academies Press, Washington, DC.
Örnek, E., and Drakopoulos, A. (2007). “Analysis of run-off-road crashes in relation to roadway features and driver behavior.” Proc., 2007 Mid-continent Transportation Research Symp., Univ. of wisconsin, Madisen, WI.
Souleyrette, R., McDonald, T., Hans, Z., Kamyab, A., Welch, T., and Storm, B. (2001). “Paved shoulders on primary highways in Iowa: An analysis of shoulder surfacing criteria, costs, and benefits.” Iowa State Univ., Ames, IA.
Tarko, A. P., et al. (2000). “Crash reduction factors for improvement activities in Indiana.” Joint Transportation Research Program, Purdue Univ., West Lafayette, IN.
Zegeer, C. V., Huang, H. F., Stewart, J. R., Pfefer, R., and Wang, J. (1998). “Effects of a two-way reporting threshold on crash analysis results.”, Transportation Research Board, Washington, DC, 49–57.
Zegeer, C. V., Stewart, R., Council, F. M., and Neuman, T. R. (1994). “Crash relationships of roadway width on low-volume roads.”, Transportation Research Board, Washington, DC, 160–168.
Information & Authors
Information
Published In
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Sep 27, 2012
Accepted: May 21, 2013
Published online: May 23, 2013
Published in print: Oct 1, 2013
Discussion open until: Oct 23, 2013
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.