EkoZAra - Emission minimizing ramp metering for multiple motorway entries

In Eko ZAra, a coordinated ramp metering system will be developed with minimisation of total traffic emissions on the motorway and the surrounding urban roads networks as an objective function. An existing subarea network containing a motorway with several entrances and connecting urban roads will be modelled with a microscopic traffic simulator and an instantaneous emission model. Increasing car travel demand and the lack of further expansion of roads induces congestions on many motorways in metropolitan areas during peak periods. Congestion frequently starts to build up at bottlenecks in the motorway network which may cause delays on the on-ramps and furthermore disturbances on the adjacent urban road network. The initial capacity drop on the motorway occurs within time periods which need additional capacity the most. Besides the annoyance of congestion induced delays, congestion causes a surplus on emissions and fuel consumption and a negative impact on traffic safety. Several highway agencies worldwide implement ramp metering to maintain stable traffic conditions on the main motorway as long as possible. In Eko ZAra, a coordinated ramp metering for a sequence of entries will be developed further using emissions as an objective function. The system aims to minimise the total traffic induced emission of a road network consisting of a motorway with several junctions and connecting secondary roads. The developed ramp metering system will be verified using a microscopic traffic flow model, an instantaneous emission model for cars and trucks and a subarea network of the city of Linz. Major scientific advancements will be: Further development of an existing coordinated ramp metering system with minimization of traffic emissions as a new objective function; Enhancements of the functionality of traffic induced emission modelling using microscopic traffic flow modelling (VISSIM) and instantaneous emission calculation (PHEM). DOE (Design Of Experiment) as a sophisticated methodology to identify the best parameter setting within a large choice set using genetic algorithms. The ramp metering system with a parameter set minimizing emissions will be applied at a virtual testsite. A subarea network of Linz will be simulated to identify the potential total savings in emissions and fuel consumption. The ramp metering system will be linked with additional traffic signals on the secondary road network as well as making use of the dynamic speed control system being a major backbone of the traffic management system of the ASFINAG. The coordinated ramp metering system will be developed and tested using a subarea network in the conurbation of Linz, the capital of Upper Austria. All major administration, ASFINAG, the state council of Upper Austria and the city of Linz will participate within Eko ZAra. The traffic flow model within the merging zones requires additional calibration which will be conducted using GPS trajectory records supplemented by video data analysis. Cost-benefit analysis will be carried out as decision support for potential actions. Beside, Eko ZAra gives a promising possibility to serve as a measure in terms of the traffic management edict (IG-L, BGBl. II Nr. 302/2007) in redevelopment areas according to the pollution-protection-act (IG-L, BGBl. I Nr. 115/1997).