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OML-Highway model applications

The OML-Highway model is intended for the applications listed below:

Environmental Impact Assessment (EIA)– to improve information about air pollution as part of legal requirements to assess environmental impacts of new major highway constructions or major alteration of existing highways.

EU Ambient Air Quality Limit Values – to be able to assess current or future air quality levels along highways in relation to European Union air quality limit values.

Systematic Mapping of Air Quality and Human Exposure – to provide overview of the current and future state of air quality and human exposure along a large road network to identify hot spots and areas that merit further analysis and assessment of mitigating measures.

“What-If” Scenario Analysis – to predict present and future air quality levels under different scenario assumptions e.g. construction of noise barriers, changed traffic volumes or vehicle composition, and change in emissions.

The illustration is an example of modeled annual mean of NO2 in 2020 for all residential addresses within a distance of 1,000 meters of the existing motorway crossing the inlet of Limfjorden in Denmark (to the right) and a new proposed crossing (Lindholm alternative – to the left). The EIA study evaluated impacts on emissions and air quality of different alternatives for new motorway crossings of the Inlet of Limfjorden in the north part of Jutland in Denmark (Jensen et al. 2011a).


Other EIA studies using the OML-Highway have been performed for a widening of an existing motorway (from two to three lanes in each direction) around the city of Odense in Denmark (Jensen et al. 2011b). Another example is an EIA of different alignments of motorways and highway sections between the cities of Aarhus and Viborg in Denmark (Jensen et al. 2011c).


All three studies were carried out for the Danish Road Directorate as part of EIA studies.