The NAO audits the accounts of the Department for Transport, its
executive agencies and some public bodies it sponsors. The NAO also
examines the systems that underlie the data collection for
measuring the progress of the Department against its Public Service
Agreement targets.
The NAO does not examine local transport expenditure directly,
as Local Authorities spend that money, and they are audited by the
Audit Commission. Transport matters outside England are audited by
respective Audit offices.