Direct Usage of Occupancy Data for Multiregime Speed-Flow Rate Models
Publication: Journal of Transportation Engineering, Part A: Systems
Volume 149, Issue 1
Abstract
Early macroscopic traffic flow models were based on observations of volume, speed, and density. The invention of traffic sensors has supplied a wealth of data for the development of more accurate macroscopic flow models. However, traffic sensors typically collect volume, speed, and occupancy data. Researchers prefer to convert occupancy to density because of the density usage in earlier models; however, for this conversion, the average length of passed vehicles must be determined. This length is frequently estimated by researchers. However, because the explanatory variable (density) is not observed but produced, this estimation weakens the model results. Considering these challenges, this research proposes a novel traffic flow modeling approach based on occupancy. The proposed method was tested in three speed-flow rate relationship regions, one of which is congested and two of which are free flow. Free flow speed, capacity, queue discharge flow, breakpoint flow rate, and optimum speed can all be determined more precisely with this method. Furthermore, the nonlinear relationship between speed and flow rate was clarified. The proposed traffic flow model is extremely useful, especially for dynamic traffic management applications, because it is based on directly gathered data such as volume, speed, and occupancy.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
References
Ambühl, L., A. Loder, M. Bliemer, M. Menendez, and K. W. Axhausen. 2020. “A functional form with a physical meaning for the macroscopic fundamental diagram.” Transp. Res. Part B Methodol. 137 (Jul): 119–132. https://doi.org/10.1016/j.trb.2018.10.013.
Athol, P. 1965. “Interdependence of certain operational characteristics within a moving traffic stream.” Highway Res. Rec. 72 (Aug): 58–87.
Banks, J. H. 1995. “Another look at a priori relationships among traffic flow characteristics.” Transp. Res. Rec. 1510 (1): 1–10.
Cassidy, M. J., and R. L. Bertini. 1999. “Some traffic features at freeway bottlenecks.” Transp. Res. Part B Methodol. 33 (1): 25–42. https://doi.org/10.1016/S0191-2615(98)00023-X.
Cassidy, M. J., and J. R. Windover. 1995. “Methodology for assessing dynamics of freeway traffic flow.” Transp. Res. Rec. 1484 (1): 73–79.
Ceder, A., and A. D. May. 1976. “Further evaluation of single-and two-regime traffic flow models.” Transp. Res. Rec. 567 (Jan): 1–15.
Del Castillo, J. M. 2012. “Three new models for the flow–density relationship: Derivation and testing for freeway and urban data.” Transportmetrica 8 (6): 443–465. https://doi.org/10.1080/18128602.2011.556680.
Del Castillo, J. M., and F. G. Benitez. 1995. “On the functional form of the speed-density relationship-I: General theory.” Transp. Res. Part B Methodol. 29 (5): 373–389. https://doi.org/10.1016/0191-2615(95)00008-2.
Drake, J. S., J. L. Schofer, and A. D. May. 1967. “A statistical analysis of speed density hypotheses.” Transp. Res. Rec. 154 (Jun): 112–117.
Easa, S. M. 1983. “Selecting two-regime traffic flow models.” Transp. Res. Rec. 869 (Aug): 25–36.
Easa, S. M., and A. D. May. 1980. “Generalized procedure for estimating single-and two-regime traffic-flow models.” Transp. Res. Rec. 772 (1): 24–37.
Edie, L. C. 1961. “Car-following and steady-state theory for noncongested traffic.” Oper. Res. 9 (1): 66–76. https://doi.org/10.1287/opre.9.1.66.
Gerlough, D., and M. J. Huber. 1975. Traffic flow theory—A monograph. Washington, DC: Transportation Research Board.
Geroliminis, N., and C. F. Daganzo. 2008. “Existence of urban-scale macroscopic fundamental diagrams: Some experimental findings.” Transp. Res. Part B Methodol. 42 (9): 759–770. https://doi.org/10.1016/j.trb.2008.02.002.
Greenberg, H. 1959. “An analysis of traffic flow.” Oper. Res. 7 (1): 79–85. https://doi.org/10.1287/opre.7.1.79.
Greenshields, B. D. 1935. “A study of traffic capacity.” Highway Res. Board Proc. 14 (Jan): 448–477.
Hall, F. L., B. L. Allen, and M. A. Gunter. 1986. “Empirical analysis of freeway flow-density relationships.” Transp. Res. Part A Policy Pract. 20 (3): 197–210. https://doi.org/10.1016/0191-2607(86)90094-4.
Hall, F. L., and M. A. Gunter. 1985. “Further analysis of the flow-concentration relationship.” Transp. Res. Rec. 1091 (1): 1–9.
Hall, F. L., V. F. Hurdle, and J. H. Banks. 1992. “Synthesis of recent work on the nature of speed-flow and flow-occupancy (or density) relationships on freeways.” Transp. Res. Rec. 1365 (1): 12–18.
Hall, F. L., and B. N. Persaud. 1989. “Evaluation of speed estimates made with single-detector data from freeway traffic management systems.” Transp. Res. Rec. 1232 (1): 9–16.
Kim, Y., and F. L. Hall. 2004. “Relationships between occupancy and density reflecting average vehicle lengths.” Transp. Res. Rec. 1883 (1): 85–93. https://doi.org/10.3141/1883-10.
Kockelman, K. M. 1998. “Changes in flow-density relationship due to environmental, vehicle, and driver characteristics.” Transp. Res. Rec. 1644 (1): 47–56. https://doi.org/10.3141/1644-06.
Leclercq, L. 2005. “Calibration of flow–density relationships on urban streets.” Transp. Res. Rec. 1934 (1): 226–234. https://doi.org/10.1177/0361198105193400124.
May, A. D. 1990. Traffic flow fundamentals. Englewood Cliffs, NJ: Prentice-Hall.
Öğüt, K. S., and J. H. Banks. 2005. “Stability of freeway bottleneck flow phenomena.” Transp. Res. Rec. 1934 (1): 108–115. https://doi.org/10.1177/0361198105193400111.
Pushkar, A., F. L. Hall, and J. A. Acha-Daza. 1994. “Estimation of speeds from single-loop freeway flow and occupancy data using cusp catastrophe theory model.” Transp. Res. Rec. 1457 (1): 149–157.
Roess, R. P. 2011. “Speed-flow curves for freeways in highway capacity manual 2010.” Transp. Res. Rec. 2257 (1): 10–21. https://doi.org/10.3141/2257-02.
Schoen, J., A. May, W. Reilly, and T. Urbanik. 1995. Speed-flow relationships for basic freeway sections. Tucson, AZ: JHK & Associates.
Tanış, M. 2013. “An investigation of the factors affecting the free flow speed and capacity for basic freeway segments of urban freeways.” [In Turkish.] Ph.D. thesis, Dept. of Civil Engineering, Istanbul Technical Univ.
Transportation Research Board. 2010. Highway capacity manual. Washington, DC: National Research Council.
Underwood, R. T. 1961. “Speed, volume and density relationships.” In Quality and theory of traffic flow, 141–188. New Haven, CT: Yale Univ.
Wang, S., X. Chen, and X. Qu. 2021. “Model on empirically calibrating stochastic traffic flow fundamental diagram.” Commun. Transp. Res. 1 (Dec): 100015. https://doi.org/10.1016/j.commtr.2021.100015.
Wang, W., and Y. Wu. 2021. “Is uncertainty always bad for the performance of transportation systems?” Commun. Transp. Res. 1 (Dec): 100021. https://doi.org/10.1016/j.commtr.2021.100021.
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Published In
Journal of Transportation Engineering, Part A: Systems
Volume 149 • Issue 1 • January 2023
Copyright
© 2022 American Society of Civil Engineers.
History
Received: Apr 6, 2022
Accepted: Aug 8, 2022
Published online: Oct 20, 2022
Published in print: Jan 1, 2023
Discussion open until: Mar 20, 2023
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