Harmful NOx emissions from trucks have been halved in only five years, according to new government statistics released by the Department for Transport.

The DfT figures show a 52 per cent fall between 2013 and 2018 as haulage firms have upgraded their fleets to include cleaner Euro 6 engines.

The data was welcomed by the RHA, which said its latest predictions showed NOx emissions from HGVs will have reduced by more than 80 per cent by the end of 2025.

However, the Association warned many operators face an uncertain future as local authorities press on with plans which will see hauliers charged up to £100 per day to enter clean air zones.

These efforts to improve air quality, it said, will fall short until they proportionately target sources of emissions.

“The government is signing off poorly conceived measures which punish hauliers for local authority failures to keep emissions in check,” said RHA boss, Richard Burnett.

“But we’re leading the way – we’ve more than halved our NOx emissions in the last five years and this will only continue as firms upgrade their fleets.”

RHA said trucks and buses accounted for a small, declining proportion of NOx emissions, according to National Atmospheric Emissions Inventory data.

It cited figures from 2015, which showed the sectors were responsible for only 7.6 per cent of NOx, while the share from other key sources such as ‘passenger cars’ and ‘combustion in industry’ were much higher.