The street where Scotland's first low emission zone has had the biggest impact on pollution

Scotland’s first low emission zone (LEZ) has led to some pollution being cut by as much as one third on one street, a new study into the impact of the measure has shown.

Nitrogen dioxide (NO2) levels on High Street at the eastern edge of Glasgow’s zone were down by 35 per cent at weekends and by 25 per cent to 27 per cent on weekdays because of reduced traffic, according to research led by the University of Glasgow.

High Street in Glasgow saw weekend nitrogen dioxide reductions of 35 per cent | Jane Barlow/PA

In Hope Street at the centre of zone, a 9-13 per cent reduction was also recorded on weekdays despite unchanged traffic patterns. The university said the results “suggested the establishment of the LEZ discourages high-emission vehicles in the city centre and helps improve air quality”.

The dotted line shows Glasgow city centre's low emission zone boundary | Glasgow City Council

A ban on the most polluting vehicles started for cars and most other vehicles in June last year, with residents’ vehicles and taxis with temporary exemptions being added this June. This followed progressive restrictions on buses without the cleanest engines from 2018.

Enforcement has generated fines of more than £1.2 million.

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A separate city council study said NO2 was “marginally” above its target levels on Gordon Street, which runs past the front of Glasgow Central Station, and at the Heilanman’s Umbrella, where Argyle Street passes under the station.

Glasgow's city centre low emission zone has been enforced since June | John Devlin/The Scotsman

It said there was poor dispersion of pollutants at the latter location, which is a busy public area. The council also highlighted that Hope Street only narrowly met pollution targets.

Its report showed NO2 levels last year were 24.4 per cent lower in George Square compared to 2022, and 18 per cent lower in Union Street and Bath Street.

The study said that as the LEZ was in force for only half of 2023, when it did not yet apply to residents or 778 non-compliant taxis, it was too soon to determine the zone’s full impact on air quality.

Qunshan Zhao, professor in urban analytics at the university, said of its study: “These early results indicate that while traffic reductions and the decrease of the high-emission vehicles in some parts of the city may be contributing to improved air quality, other factors may also play a role.”

A council spokesperson said: “The university research provides encouraging initial evidence that Glasgow’s LEZ is an effective method of contributing towards air quality improvements, as has been observed in the hundreds of similar established schemes across Europe.”

The council said revenue from fines would be spent on a range of environmental projects such as tree planting.

Stuart Patrick, chief executive of Glasgow Chamber of Commerce, said: “The improvement in air quality linked with the LEZ comes as welcome news. However, we must ensure the focus on revitalising the city is just as much of a priority.

“We know that both footfall and sales within the city have been heavily impacted this year, and while this is linked to a number of factors such as the cost-of-living crisis, businesses operating in the city centre are concerned about the LEZ rollout without proper investment in public transport offerings alongside sustained maintenance of the centre streets.”

LEZs have also been enforced in Edinburgh, Aberdeen and Dundee city centres since June.