Dr Gary Fuller's latest Pollution Watch for the Guardian newspaper briefly describes changes in nitrogen dioxide from traffic pollution from our changed lives, see: https://www.theguardian.com/environment/2020/oct/08/covid-19-lockdowns-global-air-quality-india-london-uk

As the article highlights, the improvements in air pollution due to modified travel patterns have not been the same everywhere; decreases have been seen in central areas and close to London’s airports but concentrations on some suburban roads have returned to pre-Covid levels in the last month. The figure below shows the daily pattern in weekday nitrogen dioxide alongside two roads in London. In each case, Green = pre-lockdown, red = full lockdown, orange = non-essential shops & hospitality open, yellow = September when schools re-opened. The daily traffic patterns can be seen with morning and evening rush hours. The gradual deterioration is clear, as is return to pre-lockdown at the inner suburban road.