Quantifying the impact of low- and zero- emission zones: Evidence Review - for the Clean Cities Campaign

The outputs from the project will be used to support the work of the Clean Cities Campaign on the upcoming proposal for the revision of the Ambient Air Quality Directive. [...] 10-12009C-10 9 October 2022 Quantifying the impact of LEZs and ZEZs: Evidence Review Enforcement The level and stringency of enforcement will, alongside the severity of the penalties for non-compliance, have an influence over the level of compliance and thus the impact of the zone. [...] The ULEZ was implemented in central London in 2019, prior to lockdowns resulting from the Covid-19 pandemic, the easing of which can be seen in the uplift in the red line in the graph. [...] along the lines of the greater than 95% reduction in traffic related NOX emissions projected for Oxford and Amsterdam), but this depends on when they are introduced, and thus the relative change in the fleet, and the proportion of the fleet they cover. [...] This is mainly due to (1) the problems of constructing a robust counterfactual and (2) in isolating the effect of the zone from the wider changes to the vehicle fleet and driver/operator behaviours (as well as wider societal changes, such as the response to the Covid-19 pandemic, or the current energy crisis).