Emissions from real-world driving are often higher than estimated emission levels calculated based on Euro emissions standards and laboratory tests.

This has given rise to diesel emission scandals and, consequently, the air quality in cities has not improved as much as was originally anticipated from stringent emission regulations in European regions and associated renewals of vehicle fleets.

Professor Bidisha Ghosh from Trinity’s School of Engineering is the principal investigator on the REDMAP project. She said: “The expected reduction in emissions from road transport has not been achieved satisfactorily in Ireland or in the wider EU, owing largely to discrepancies between real-world driving emissions and expected emissions according to European standards.”

Premature deaths

“More than half a million premature deaths occurred in 2016 in the WHO European region from household and ambient air pollution. Due to the high density of on-road vehicles and proximity of pollutant generation to high density urban dwellings the impact of air pollution is higher in urban areas such as Dublin, so it is imperative that projects such as REDMAP accurately assess the true levels of traffic emissions.”

Due to a carbon dioxide (CO₂) based vehicle taxation system introduced in 2008, there is a significant demand for diesel vehicles in Ireland (55% of all new vehicle purchase were diesel in 2018). At present, diesel vehicles are the largest contributor to CO₂ and PM2.5 emissions in the country.

Additionally, in 2015, the Trinity research team estimated that the diesel fleet alone would cause a total damage of 663.1 million euro from air pollution in the 10 years to 2025 in Ireland. To deal with this effectively, the first step is to estimate the real levels of air pollutant generation.

The REDMAP project team comprises engineers from Trinity, University College Dublin and Ricardo from the UK. The team will measure and model real-world emissions using Remote Sensing (RS) and Portable Emission Measurement Systems (PEMS) from more than 150,000 vehicles at four locations over a 16-week period in Dublin.

The real emission contribution of different vehicles considering Euro standards, fuel type, make, and categories and vehicle modifications will be verified. This will also help to improve the air pollution estimates of the National Emission Inventory (NEI).

The European Commission (EC) has introduced new Real Driving Emissions (RDE) legislation for all new vehicles starting from September 2019. The REDMAP project will be one of the first in the EU and the first in Ireland to investigate the implementation of RDE testing.

It will also develop a framework of real transport emission monitored utilising RS and then PEMS technology to calculate real-driving emission factors (RD-EF).

A new traffic-emission model and paired air quality model estimating pollutant concentrations will be developed based on real-world emission factors (RD-EF).

The modelling framework will illustrate the potential environmental, economic and health impacts of real emission due to new RDE legislation, related policy changes and future growth considering hypothetical scenario-based modelling.

Ultimately, the project will generate guidelines on measures and opportunities to reduce actual vehicular emission on roads in Dublin.