As at May 2022, a lifetime budget of £883 million has been committed to the NO2 Programme to support local authorities. Separately government has spent £39 million to improve air quality on the Strategic Road Network from 2015–16 to 2019–20. Further funding is available to 2024–25.37 Although the NO2 programme is the largest dedicated air quality initiative, other work across government is expected to contribute to improving air quality, such as support to ultra-low emission vehicles and the Transforming Cities Fund, which improves public and sustainable transport. Government could not provide the National Audit Office with a breakdown of committed and actual spend across its portfolio of air quality initiatives.38 DfT told us that it has carried out deep dives in specific areas, such as on air quality benefits from meeting Net Zero commitments over the period from 2020 to 2050, but that carrying out similar work across the full span of Government programmes on an annual basis would be technically difficult.39