Low Emission Zones (LEZs) designed to improve air quality and were introduced across Aberdeen, Dundee, Edinburgh and Glasgow were introduce last year.

Source: https://www.heraldscotland.com/news/homenews/23396493.scotlands-use-public-transport-drops-half/?ref=rss

Low emission zones (LEZs) have been hailed as a way to reduce urban air pollution.

Source: https://www.inverness-courier.co.uk/news/fergus-ewing-does-inverness-need-to-be-a-low-emissions-zone-324703/

Scientists have said that lowering air pollution from traffic in cities through LEZs and congestion charging zones (CCZs) has a measurable benefit to public health.

Source: https://www.glasgowtimes.co.uk/news/23794745.glasgow-city-council-vehicles-dont-comply-lez/?ref=rss