Interactive tool shows the effect of Glasgow's LEZ on pollution

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The Scottish Environment Protection Agency (SEPA) has published a new interactive tool that enables users to chart the success of the first phase of Glasgow’s Low Emission Zone (LEZ).

Ahead of the launch of phase 2 of the city’s LEZ on Thursday 1 June, air quality experts from the agency are helping reflect on the progress made in tackling harmful nitrogen dioxide (NO2) levels in the city over the last five years.

Published online, the tool follows the city’s bus fleet’s journey to full compliance with current emissions standards and showcases how pollution has been driven down in some of the busiest bus corridors.

All buses in the zone now meet the EURO VI bus standard - the strictest emissions standard - from a place of just 19 per cent compliance before the scheme. Some operators have also gone beyond the standard with their electric vehicles.

Meanwhile, air quality monitoring in the city saw levels of NO2 fall in 2022 along key bus corridors to the lowest levels outside of the pandemic - in the case of Hope Street, meeting air quality objectives for the first time.

Dr Andrew Malby of SEPA said:

“Phase one of Glasgow’s LEZ focused on the city’s buses and, using data collected by Glasgow City Council and bus operators, we’ve been able to show the improvements in air quality as the fleet underwent significant improvements.

“While the focus has been along bus corridors, improvements are also now required in all other areas of the city centre. This will be achieved during the next phase of the LEZ when all vehicles are required to meet emission standards.”

The development of Glasgow's LEZ was undertaken through close partnerships between SEPA, Glasgow City Council, Transport Scotland and major public transport operators.

Cllr Angus Millar, Glasgow City Council Convener for Transport and Climate said:

“Poor air quality presents a serious risk to public health and so the LEZ is an essential measure if Glasgow is to tackle the harmful air pollution that has dogged parts of the city centre for decades. With the success of the bus phase, it’s clear that expansion to include all types of vehicles will allow us to maximise the LEZ’s air quality benefits.

“While evidence suggests air quality improvements in city centre streets where buses were historically the main drivers of air pollution, we still have stubbornly high levels of harmful air pollution throughout the city centre – and while up to 90% of vehicles entering the zone will be unaffected by the LEZ, restricting access to the remaining minority of vehicles that pollute the most is vital to protect public health.

“Glasgow is the first of Scotland’s four biggest cities to introduce a Low Emission Zone, but we are joining hundreds of cities across Europe where similar initiatives are already making a positive impact. Expansion of Glasgow’s LEZ to cover all vehicle types will further tackle harmful and dirty air in our city centre, ensuring it’s a safer and more pleasant place to live, work and visit.”

Transport Minister Kevin Stewart said: “I’m really pleased to see these positive achievements in air quality, which show that the actions being put in place are delivering for the people of Scotland.

“The Scottish Government remains committed to tackling air pollution to improve air quality and public health and Scotland’s LEZs are key to further improving air quality in our city centres, making them even more attractive places to live, work, shop and spend leisure time in.

“Many vehicles already meet the LEZ standard, with petrol cars from 2006 or newer, and diesel cars from September 2015 or newer generally being compliant. People can now enter their vehicle registration number on the official website for Scotland’s Low Emission Zones to confirm if their vehicle will comply.”

From Thursday 1 June 2023, phase 2 of the Low Emission Zone (LEZ) will come into force. Vehicles entering the city centre zone will be required to meet EURO 6/VI emissions standards for diesel vehicles or EURO 4/IV for petrol vehicles. The LEZ will be enforced through penalty charges for any vehicles entering the zone that does not meet these standards.

Find out more about Glasgow’s LEZ at

To view the data tool, visit