Investigation of the emission and air quality impacts of low emission zone scenarios in Newcastle and Gateshead, UK

Many cities in the UK and EU are failing to meet standards for NO₂. In the UK, 63% of UK Local Authorities out of a total of 403 Local Authorities have declared one or more Air Quality Management Areas (AQMAs) in 2011, which is a significant increase compared to the corresponding figure of 29% in 2003. The number of AQMAs declared for NO₂ has risen by nearly 350% from 160 to 549 AQMAs, during the same period. This has prompted local authorities to develop local transport plans to manage traffic levels and also explore ways to reduce vehicular emissions in the areas which are failing to meet NO₂ standards. Low Emission Zones (LEZ) have been designed in many European cities to achieve the latter. As the aim of an LEZ is to reduce concentrations of airpollutants within its boundaries, generally those vehicles with the largest gross contribution to emissions are targeted initially. This study presents the results of a joint Low Emission Zone investigative study proposed by Newcastle and Gateshead local authorities in the UK. A base year of 2010 was set up and then seven scenarios, for the year 2021, were investigated with varying degrees of penetration of new technology vehicles. The seven scenarios for 2021 included a business as usual scenario and six others with different mix of vehicle fleet (all vehicles Euro 5/V compliant; all vehicle Euro 6/VI compliant; only goods vehicles Euro V compliant; only goods vehicles Euro VI compliant; all buses Euro VI compliant; and all cars Euro 6 compliant). For scenarios where the Euro 6/VI regulations were assumed effective it was found that general fleet turnover and renewal over the 2010 to 2021 period, coupled with emissions improvements in other sectors, lead to an approximate 45% reduction (equivalent to 10 - 15 μg/m³) in mean NO₂ concentrations for receptor points in Newcastle City and Gateshead Air Quality Management Areas. This reduction by itself is sufficient to significantly reduce the chances of exceedence of the National Air Quality Standard for annual mean NO₂ (currently 40 μg/m³) in those areas, though the potential for 'hot-spot areas' with excessively high concentrations may remain.