Traffic conflict points at intersections are the points at which traffic movements intersect (including crossing, merge, and diverge). Numbers and distribution of conflict points have been used to evaluate intersection access management designs and safety performance. Traditionally, determination of numbers of conflict points for different traffic movements has been based on manual methods, which causes the difficulty for computerized procedures to evaluate safety performance of different access management designs.
Documents in the Category: Effects
Liu, P., J. Lu and H. Chen, Safety effects of the separation distances between driveway exits and downstream U-turn locations, Accident Analysis and Prevention, Vol. 40, Issue 2 (2008)
Highway Safety Manual, American Association of State Highway and Transportation Officials, Washington, D.C. (2010).
Rawlings, J. and J. Gattis, Detailed Study of Driveway Collision Patterns in an Urban Area, Transportation Research Board 87th Annual Meeting (2008)
Gans, A., J. Shen, and A. Rodriguez, Update of Florida Crash Reduction Factors and Countermeasures to Improve the Development of District Safety Improvement Projects, prepared for the Florida Department of Transportation, (2005)
Eisele, W. and C. Toycen, Evaluating the Relative Safety of Access Management Treatments in Micro-Simulation, 10th National Conference on Transportation Planning for Small and Medium-Sized Communities (2006)
VHB. Safety Evaluation of Access Management Policies and Techniques, Federal Highway Administration (contract in progress).
The objectives of this ongoing research are to:
1. Develop evaluation models to assess the safety impact of access management policies and treatments relevant to urban, urbanizing, and suburban arterials.
2. Propose an access management evaluation framework that can be adopted by state and local agencies to evaluate compliance of access management policies, and the impacts of viable access treatment techniques.
Schultz , G., J. Lewis, and T. Boschert, Safety Impacts of Access Management Techniques in Utah, Transportation Research Record: Journal of the Transportation Research Board, No. 1994, Transportation Research Board of the National Academies, Washington, D.C., (2007, pp. 35-42). [Schultz, G. and J. Lewis, Assessing the Safety Benefits of Access Management Techniques, Brigham Young University, Utah Department of Transportation (2006)]
Potts, I. B., D. W. Harwood, D. J. Torbic, K. R. Richard, J. S. Gluck, H. S. Levinson, P. M. Garvey, R. S. Ghebrial, NCHRP Report 524: Safety of U-Turns at Unsignalized Median Openings, Transportation Research Board of the National Academies, Washington, D.C. (2004)
Potts, I., Harwood, D., and Richard, K. Relationship of Lane Width to Safety for Urban and Suburban Arterials, Presented at the 86th Annual Transportation Research Board meeting, Washington, D.C. (2007).
Mauga, T. and M. Kaseko, Modeling and Evaluating Safety Impacts of Access Management Features in Las Vegas, Nevada, Valley, Transportation Research Record: Journal of the Transportation Research Board, No. 2171, Transportation Research Board, Washington D.C. (2010) pp. 57-65
Gattis, J., Safety Effects of Access Design Decisions ITE 2008 Technical Conference and Exhibit (2008)
This paper contains a detailed literature review of studies which have examined and reported safety of designs and operational features that contribute to managing access along roadways. It also presents trends found among the findings reported in these previous studies.
Zhang, G. and J. Lu, Study on Unsignalized Access Points Using Microscopic Traffic Simulation, Seventh International Conference on Traffic and Transportation Studies (2010)
Zhu, Z., and J. Rong, The Impact of the Accesses on the Operating Speed of Two-Lane Highways, Proceedings of the 10th International Conference of Chinese Transportation Professionals (2010)
Liu, P., F. Hu and J. Lu, Operational Effects of Right Turns Followed by U-Turns at Signalized Intersections as Alternatives to Direct Left-Turns from Driveways, Advances in Transportation Studies, Vol. 11 (2007)
Lu, J., P. Liu, G. Sokolow and F. Pirinccioglu, Operational Effects of U-Turns as Alternatives to Direct Left Turns from Driveways or Side Streets: Some Research Findings in Florida, Transportation Research Board 85th Annual Meeting (2006)
Lu, J. et al, Methodology to Quantify the Effects of Access Management on Roadway Operations and Safety, 3 volumes, prepared by the University of South Florida for the Florida Department of Transportation, Tampa, FL, (2001)
Fitzsimmons, E., S. Hallmark, D. Plazak and K. Giese, Evaluating Change in Corridor Operations Based on Access Management Strategies Using VISSIM Along US-69 Through Ankeny, Iowa, Transportation Research Board 89th Annual Meeting (2010)
Eisele, W.L. and W.E. Frawley, Estimating the Safety and Operational Impact of Raised Medians and Driveway Density: Experience from Texas and Oklahoma Case Studies, Transportation Research Record 1931, Transportation Research Board of the National Academies, Washington, D.C. (2005)
Eisele, W.L., Y. Zhang, E.S. Park, and R. Stensrud, Incorporating Driveway Density into an Arterial Corridor Travel Time Index Estimation Model, 10-2670, TRB 89th Annual Meeting Compendium of Papers DVD, Washington, D.C. (2010)
Dowling, R., et.al., NCHRP Report 616, Multimodal Level of Service Analysis for Urban Streets, TRB, Washington DC, (2008)
Chowdhury, M., N. Derov, T. Paulin, and A. Sadek, Prohibiting Left-turn Movements at Mid-Block Unsignalized Driveways: Simulation Analysis. Journal of Transportation Engineering, Vol. 131, No. 279 (April 2005), pp. 279-285
Wan, F., Y. Zhang and K. Fitzpatrick, Analysis of Platoon Impacts on Left-Turn Delay at Unsignalized Intersections, Transportation Research Record: Journal of the Transportation Research Board, No. 2223, Transportation Research Board of the National Academies, Washington, D.C. (2011)
Lyles, R., B. Malik, A. Chaudhry, G. Abu-Lebdeh and M. Siddiqui, An Evaluation of Right-Turn-In/Right-Turn-Out Restrictions in Access Management, Prepared for the Michigan Department of Transportation, Michigan State University (2009)
[ see also Malik, B., M. Siddiqui and R. Lyles, An Evaluation of Driveway Turning Restrictions in Access Management Using Microsimulation, 90th Annual Transportation Research Board Meeting, Washington, D.C. (2011)]
Lu, Jian. Guideline Development for Minimizing Operating Speed Variance of Multilane Highways by Controlling Access Design, Transportation Research Board of the National Academies, Washington, D.C., Southeastern Transportation Center, University of Tennessee (in progress, end date noted as August 2011)