Southampton City Council has published full details of its proposed ‘Class B’ clean air zone for buses, taxis and HGVs as it goes live with a public consultation on the plans.

The city was one of five identified in Defra’s December 2015 plans as not expected to meet EU limits for NO2 by 2020 and therefore required to undertake a study to see whether there is a need for a clean air zone (CAZ). Since then, the council’s Clean Air Strategy, published in 2016, identified the need for a CAZ to address the most polluting buses, taxis and HGVs – cars and vans won’t be targeted.

The latest study – published to coincide with Clean Air Day– sets out the preferred option of a city-wide Class B clean air zone for such vehicles not meeting minimum engine emission standards (Euro 4 petrol and Euro 6 diesel); this was found to deliver the greatest total NO2 concentration reductions and wider emission improvements while an economic assessment indicated there would be a net positive economic impact and vehicle displacement and road capacity impacts were minimal.

Private vehicles would not be targeted at this stage but drivers would be encouraged to choose active and sustainable modes of travel or low emission vehicles.

Any proposed CAZ for Southampton will also be used by New Forest District Council, which was also required to undertake a study but does not currently have any exceedances.

Southampton City Council added that it was also proposing a suite of mitigation measures with the objective of supporting individuals and businesses affected by the preferred option without impacting the delivery of NO2 improvements.

The consultation – which will be accompanied by public meetings – will stay open until 13 September.

A proposal will then be submitted to the Secretary of State for Environment, Food and Rural Affairs for approval in autumn 2018.