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Potential of Ecological Benefits for the Continuous Flow Intersection
Na Wu
College of Transportation Engineering, Chang’an University
Yating Liu
College of Transportation Engineering, Chang’an University


Energy conservation and emission reduction from the transportation sector are of great significance in coping with the global energy and environmental crisis. As the bottleneck of urban road traffic, intersection burdens the urban environment greatly. When the volume of left-turn traffic is large, the continuous flow intersection (CFI) can effectively improve intersection operation efficiency. This paper first put forward the definition and application conditions of CFI. Then its mechanism for energy saving and emission reduction was analysed. CFI transformation was designed taking a typical intersection in Xi’an as an example. Operating efficiency, energy consumption and emissions of the intersection before and after CFI transformation were evaluated using the VISSIM model. The  results show that energy consumption and emissions in the intersection are greatly reduced after CFI transformation. Queue length is reduced by more than 41%. Energy consumption and pollutant emission are reduced by about 8%. Through the simulation analysis, the emission reduction benefits most when the volume of left-turn traffic is 80%–85% of the design capacity, and the ratio of leftturn
traffic over through traffic is maintained between 50% and 100%. This study suggests that CFI is suitable for large-scale promotion with careful examination.


[1] Li P, Zhao P, Brand C. Future energy use and CO2 emissions of urban passenger transport in China: A travel behavior and urban form based approach. Applied Energy. 2018;211:820–842.

[2] Hill G, Heidrich O, Creutzig F, Blythe P. The role of electric vehicles in near-term mitigation pathways and achieving the UK’s carbon budget. Applied Energy. 2009;251:113111.

[3] Liu H, Zhang Y, Zhang Y, Zhang, K. Evaluating impacts of intelligent transit priority on intersection energy and emissions. Transportation Research Part D: Transport and Environment. 2020;86:102416.

[4] Mauro R, Guerrieri M. Comparative life-cycle assessment of conventional (double lane) and non-conventional (turbo and flower) roundabout intersections. Transportation Research Part D: Transport and Environment. 2016;48:96–111.

[5] An S, Song L, Wang J, Yang L. Research status and prospect of unconventional arterial intersection design. Journal of Traffic and Transportation Engineering. 2020;20(4):1–20. DOI: 10.19818/j.cnki.1671-1637.2020.04.001.

[6] Autey J, Sayed T, El Esawey M. Operational performance comparison of four unconventional intersection designs using micro-simulation. Journal of Advanced Transportation. 2013;470(5):536–552. DOI: 10.1002/atr.181.

[7] Dhatrak A, Edara P, Bared J. Performance analysis of parallel flow intersection and displaced left-turn intersection designs. Transportation Research Record. 2010;2171:33–43. DOI: 10.3141/2171-04.

[8] Zhao J, Liu Y, Di D. Optimization model for layout and signal design of full continuous flow intersections. Transportation Letters. 2016;8(4):194–204.

[9] Yang X, Chang G, Rahwanji S, Lu Y. Development of planning-stage models for analyzing continuous flow intersections. Journal of Transportation Engineering, Part A: Systems. 2013;139(11):1124–1132. DOI: 10.1061/%28ASCE%29TE.1943-5436.0000596.

[10] Coates A, Ping Y, Koganti SG, Du Y. Maximizing intersection capacity through unconventional geometric design of two-phase intersections. Transportation Research Record. 2012;2309(1):30–38. DOI: doi/10.3141/2309-04.

[11] Coates A, Ping Y, Peng L, Ma X. Geometric and operational improvements at continuous flow intersections to enhance pedestrian safety. Transportation Research Record. 2014;2436(1):60–69. DOI: 10.3141/2436-07.

[12] Carroll D. H, Lahusen D. Operational effects of continuous flow intersection geometrics: A deterministic model. Transportation Research Record. 2013;2348. DOI: 10.3141/2348-01.

[13] Hua X, et al. Design and optimization of signalized tandem intersections with displaced left-turn. Journal of Chang’an University (Natural Science Edition). 2019;39(1):107–115,126.

[14] Jiang X, Gao S. Signal control method and performance evaluation of an improved displaced left-turn intersection design in unsaturated traffic conditions. Transportmetrica B. 2020;8(1):264–289.

DOI: 10.1080/21680566.2020.1764410.

[15] Jiang X, Gao S, Zhang L. Signal control and utility analysis of an improved displaced left-turn lane. China Journal of Highway and Transport. 2019;32(9):152–163.

[16] Luo S, Tian D, Gao X, Zhang C. Adaptive signal control for displaced left turn intersection. Journal of Transport Information and Safety. 2020;38(4):17–24,33. DOI: 10.3963/j.jssn.1674-4861.2020.04.003.

[17] Suh W, Hunter M. Signal design for displaced left-turn intersection using Monte Carlo method. KSCE Journal of Civil Engineering. 2014;18(4):1140–1149. DOI: 10.1007/s12205-014-0225-8.

[18] Zhao J, Ma W, Head K, Yang X. Optimal operation of displaced left-turn intersections: A lane-based approach. Transportation Research Part C: Emerging Technologies. 2015;61:29–48.

[19] Sun W, Wu X, Wang Y, Yu G. A continuous-flow-intersection-lite design and traffic control for oversaturated bottleneck intersections. Transportation Research Part C: Emerging Technologies. 2015;56:18–33.

[20] Qu W, et al. Statistical analysis of safety performance of displaced left-turn intersections: Case studies in San Marcos, Texas. International Journal of Environmental Research and Public Health. 2020;17(18):6446.

[21] Ahmed I, Warchol S, Cunningham C, Rouphail N. Mobility assessment of pedestrian and bicycle treatments at complex continuous flow intersections. Journal of Transportation Engineering Part A: Systems. 2021;147(5):04021017. DOI: 10.1061/JTEPBS.0000512.

[22] Sun J, Yang X. Research into microscopic traffic simulation model systematic parameter calibration: A case study of VISSIM. Computer and Communications. 2004;3:3–6.
Copyright (c) 2023 Na Wu, Yating Liu

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