Evaluation of HERO Coordinated Ramp Metering Installation at the M1/M3 Freeway in Queensland, Australia

The recently developed traffic-responsive feedback control strategy HERO (HEuristic Ramp metering cOordination), that coordinates local ramp-metering actions in freeway networks, was implemented at the M1/M3 Freeway in Queensland, Australia. HERO employs an extended version of the feedback regulator ALINEA at the local level. HERO outperforms uncoordinated local ramp metering and approaches the efficiency of sophisticated optimal control schemes. HERO has been implemented by TMR (Transport and Main Roads), the road authority for the state of Queensland, Australia, at six on-ramps of the M1/M3 Freeway. The obtained results show significant improvements in traffic throughput and travel times compared with the previously used fixed-rate ramp-metering system. A rapid economic benefit analysis concluded on a benefit-cost ratio (BCR) of 13.8:1 at a 7% discount rate, and hence a very strong economic merit for the implementation of HERO. The economic payback period for capital expenditure on this pilot is approximately 4 months.