TRADITIONAL methods of modelling traffic pollution could be under-estimating emissions by as much as 60 per cent, according to North-East scientists.

Previously, traffic emissions models have only looked at the average speed of traffic, ignoring stop-start related vehicle emissions.

Now, the team at Newcastle University have devised an improved way to model traffic pollution – which is helping local authorities gain a better understanding of whether schemes to alleviate city centre congestion will improve air quality.

The new technique looks at congestion emissions based on individual vehicle type, its speed and acceleration and, crucially, takes into account factors such as hills and nearby buildings.

Anil Namdeo, senior lecturer in transport and sustainability at Newcastle University, said: “By gaining a better understanding of how road networks are influencing emissions, councils can make more effective decisions about how to deal with congestion in our city centres and help reduce the 50,000 premature deaths in the UK each year that are associated with traffic emissions.”

Working with Durham County Council the team used this new method to assess potential traffic scenarios in Durham city centre, including the proposed schemes to introduce signals at Gilesgate and Leazes Bowl roundabouts to improve traffic flow and increase the reliability of public transport.

The findings, which have been published in the International Journal of Environment and Pollution, showed that these schemes produced a slight reduction in overall emissions of nitrogen dioxide. The research concluded the proposed schemes in isolation would not significantly improve air quality, due to the location of where congestion was occurring.

Instead, the research team helped the council to confirm that additional measures would need to be considered to reduce the volume of traffic in the city centre.

The improved modelling platform is now being used by Newcastle, Gateshead, and Leeds.