Evaluating Traffic Operation and Safety of a New Interchange Design in Comparison to System Cloverleaf Interchanges
Publication: International Conference on Transportation and Development 2022
ABSTRACT
Many existing cloverleaf interchanges were built over 60 years ago based on old design guidelines. Many of those cloverleaf interchanges have operational problems due to the inconsistency with current traffic demands. Cloverleaf interchanges create weaving areas between vehicles entering and leaving the freeway. This could cause an unsafe condition, especially in system interchanges with high speeds on freeways and low speeds on loop ramps. This research evaluates the traffic operation and safety of a new interchange design called left hook, which might show potential in mitigating cloverleaf interchange problems. The left hook interchange removes all the four weaving areas of a cloverleaf interchange. The evaluation was done using VISSIM and the Surrogate Safety Assessment Model (SSAM) in this study. Overall, 72 simulation scenarios (with over 360 runs) were tested to include various conditions in terms of traffic volumes, turning traffic ratios, traffic distributions, and truck ratios. Based on the results, the left hook interchange performed better with fewer queues, stoppages, and rear-end conflicts. However, to reach a more solid conclusion on the new design, more studies should be conducted.
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REFERENCES
Leisch, J. P., Eng, P., Morrall, J., and Eng, P. (2014). Evolution of Interchange Design in North America. 15.
Garber, N. J., and Fontaine, M. D. (1999). Guidelines for Preliminary Selection of the Optimum Interchange Type for a Specific. 109.
Cloverleaf Interchanges—Engineering_Policy_Guide. https://epg.modot.org/index.php/234.5_Cloverleaf_Interchanges.
Peter, R. (1999). Improved Safety Information to Support Highway Design, Issue 430. Transportation Research Board.
Zhong, H. (2012). Free-flow Parclo Interchange vs. the Cloverleaf Interchange with C-D Roads and the All-Directional Four-level Interchange: A Comparison of Geometrics, Construction Cost, and Right of Way Requirements.
Foody, T. J., Wray, J. H., and FHWA Office of Research & Development. (1975). Improving the Traffic Operations and Safety of Full Cloverleaf Interchange.
Oregon DOT (Oregon Department of Transportation). (2012). Highway Design Manual, Chapter 9.
Molan, A. M., and Hummer, J. (2021). Proposing the New Parclo ProgressA Design as a Substitute for the Conventional Partial Cloverleaf A Interchanges, International Journal of Modelling and Simulation, pp. 1–15, 2020.
Molan, A. M., Hummer, J., Aspeitia, L., and Deatherage, A. (2021). Evaluating safety performance of the offset diamond interchange design using VISSIM and surrogate safety assessment model, Journal of Transportation Safety & Security.
Molan, A. M., and Hummer, J. (2020). Improving Traffic Operations at Service Interchanges Using the New Offset Diamond Design. Transportation Research Record (TRR), SAGE Publishing, Vol 2674, Issue 5, 522–536.
Sutherland, L. F., Cook, D. J., and Dixon, K. K. (2018). Operational effects of the displaced partial cloverleaf interchange, Transportation research record, vol. 2672, no. 17, pp. 108–119.
Molan, A. M., Hummer, J. E., and Ksaibati, K. (2019). “Modeling safety performance of the new super DDI design in terms of vehicular traffic and pedestrian,” Accident Analysis & Prevention, vol. 127, pp. 198–209.
Hummer, J. E., and Molan, A. M. (2022). “Comparing the New Double Contraflow Intersection to Conventional and Alternative Intersections,” Journal of Transportation Engineering, Part A: Systems, vol. 148, no. 3, p. 04021123.
Molan, A. M., Howard, J., Islam, M. B., and Pande, A. (2021). Evaluation of Cost-Effective Alternative Designs for Rural Expressway Intersections, Center for Transportation, Equity, Decisions and Dollars (CTEDD).
Molan, A. M., and Hummer, J. E. (2017). “Safety analysis of the new synchronized and Milwaukee B interchanges in comparison to existing designs,” Accident Analysis & Prevention, vol. 109, pp. 29–35.
Fan, R., Yu, H., Liu, P., and Wang, W. (2013). “Using VISSIM simulation model and Surrogate Safety Assessment Model for estimating field measured traffic conflicts at freeway merge areas,” IET Intelligent Transport Systems, vol. 7, no. 1, pp. 68–77.
Liu, P., Qu, X., Yu, H., Wang, W., and Cao, B. (2012). “Development of a VISSIM simulation model for U-turns at unsignalized intersections,” Journal of Transportation Engineering, vol. 138, no. 11, pp. 1333–1339.
Caltrans. (2017). Price Index for Selected Highway Construction Items.
Caltrans. (2016). Comparative Bridge Costs.
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Published In
International Conference on Transportation and Development 2022
Pages: 277 - 286
History
Published online: Aug 31, 2022
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