Traffic&Transportation Journal
Sign In / Sign Up


Efficiency and Equity Performance of a Coordinated Ramp Metering Algorithm
Duo Li, Prakash Ranjitkar, Yifei Zhao
Keywords:ramp metering, efficiency, equity, AIMSUN,


Ramp metering (RM) has been widely applied due to its effectiveness in improving motorway traffic conditions by limiting inflow from on-ramps. A great deal of experimental and simulation-based studies have proven system-wide benefits of motorways from RM. Benefits attributed to RM in the literature include reducing travel times, increasing motorway throughputs and decreasing fuel consumption and emissions. However, RM benefits might be costing more some motorway users, e.g. some on-ramp users might be experiencing longer delay than others, which leads to an unfair allocation of RM benefits. This paper presents a coordinated ramp metering strategy, which is aimed at reducing the inequity among motorway users using different on-ramps and investigates trade-offs between efficiency and equity for the proposed strategy. Total travel time is used to measure the efficiency while Gini coefficient is used to measure equity. A combined index is proposed incorporating the two measures to serve as an objective function to solve the bi-objective control design problem. The performance of the proposed strategy is verified by comparing it to a well-established coordinated ramp metering strategy HERO using micro-simulation
software AIMSUN. Simulation results revealed that the equity of the motorway system can be improved significantly by using the proposed strategy without compromising much on the efficiency of the system.


Zhang L, Levinson D. Balancing Efficiency and Equity of Ramp Meters. ASCE Journal of Transportation Engineering. 2005;131(6):477-481.

Papageorgiou M, Papamichail I. Handbook of Ramp Metering. Document for European RAmp Metering Project (EURAMP); 2007.

Li D, Ranjitkar P. Assessing Ramp Metering and Variable Speed Limits Strategies for Auckland Motorway, Journal of Eastern Asia Society for Transportation Studies. 2013;10:1856-1871.

Li D, Ranjitkar P. Performance Evaluation of Ramp Metering Algorithms Combined with Variable Speed Limits for Auckland Motorway. 92nd Annual Meeting of Transportation Research Board; 2013 Jan 13-17; Washington DC; 2013.

Pinnell C, Drew D, McCasland W, Wattleworth I. Evaluation of entrance ramp control on a six-mile freeway section. Highway Research Record. 1967;157:22-76.

Yin Y, Liu H, Benouar H. A Note on Equity of Ramp Metering. 7th IEEE Intelligent Transportation Systems Conference; 2000 Oct 1-3; Washington, DC; 2000.

Levinson D, Zhang L, Das S, Sheikh A. Evaluating Ramp Meter: Evidence from the Twin Cities Ramp Meter Shut-off. 81st Annual Meeting of Transportation Research Board; 2002 Jan 13-17; Washington, DC; 2002.

Gini C. On the measure of concentration with especial reference to income and wealth. Cowles Commission; 1936.

Kotsialos A, Papageorgiou M, Middelham F. Optimal Coordinated Ramp Metering with Advanced Motorway Optimal Control. Transportation Research Record. 2001;1748:55-65.

Zhang L, Levinson D. Optimal Freeway Ramp Control Without Origin-destination Information. Transportation Research B. 2004;38:869-887.

Zhang HM, Shen W. Access Control Policies without Inside Queues: Their Properties and Public Policy Implications. Transportation Research B. 2010;44:132-1147.

Papamichail I, Papageorgiou M. Traffic-responsive Linked Ramp Metering Control. IEEE Transactions on Intelligent Transportation Systems. 2008;9:111-121.

Papamichail I, Papageorgiou M, Vong V, Gaffney J. Heuristic Ramp-Metering Coordinated Strategy Implemented at the Monash Freeway. Transportation Research Record. 2010;2178:10-20.

Minnesota Department of Transportation. Stratified Zone Metering-The Minnesota Algorithm. MnDOT, Minnesota; 2003.

Li D, Ranjitkar P, Ceder A. An Integrated Approach to Combine Ramp Metering and Variable Speed Limits to Improve Motorway Performance. Transportation Research Record. 2014;2470:86-94.

Li D, Ranjitkar P. A Fuzzy Logic-based Variable Speed Limit Controller. Journal of Advanced Transportation. 2015;49(8):913-927.

Lakshmanan T, Nijkamp P, Rietveld P, Verhoef E. Benefits and Costs of Transport: Classification, Methodologies and Policies. Regional Science. 2001;80:139-164.

Hasan M, Ha M, Ben-Akiva M. Evaluation of Ramp Control Algorithms Using Microscopic Traffic Simulation. Transportation Research Part C. 2002;10(c):229-256.

Papageorgiou M, Haj-Salem H, Middclham F. ALINEA Local Ramp Metering: Summary of Field Results. Transportation Research Record. 1997;1603:90-98.

Kesten A, Ergün M, Yai T. An Analysis on Efficiency and Equity of Fixed-Time Ramp Metering. Journal of Transportation Technologies. 2013;3:48-56.

Zhang L, Levinson D. Balancing efficiency and equity of ramp meters. 82nd Annual Meeting of Transportation Research Board; 2003 Jan 12-16; Washington DC; 2003.

Jacobson L, Henry K, Mahyar O. Real-time Metering Algorithm for Centralized Control. Transportation Research Record. 1989;1232:17-26.

Kotsialos A, Papageorgiou M. Efficiency and Equity Properties of Freeway Network-wide Ramp Metering with AMOC. Transportation Research Part C. 2003;12:401-420.

Lorenz MO. Methods of Measuring the Concentration of Wealth. Publication of the American Statistical Association; 1905.

Levinson D, Zhang L, Das S, Sheikh A. Ramp meters on trial: evidence from the Twin Cities ramp meters shutoff. 81st Annual Meeting of Transportation Research Board; 2002 Jan 13-17; Washington, DC; 2002.

Papageorgiou M, Hadj-Salem H, Blosseville JM. ALINEA: a Local Feedback Control Law for Onramp Metering. Transportation Research Record. 1991;1320:58-64.

TSS. AIMSUN 7 Dynamic Simulators User`s Manual. Transport Simulation Systems; 2012.

Copyright (c) 2023 Duo Li, Prakash Ranjitkar, Yifei Zhao

Published by
University of Zagreb, Faculty of Transport and Traffic Sciences
Online ISSN
Print ISSN
SCImago Journal & Country Rank
Publons logo
© Traffic&Transportation Journal