As well as recovering the cash, Transport for London (TfL) also seized more than 530 vehicles in lieu of outstanding fines. With more than 97% of vehicles driving in the ULEZ complying with the emissions standards, TfL says it is targeting a specific group of drivers who persistently refuse to pay multiple outstanding penalties. This has led to around £16.5m of debt related to road user charges and penalties being recovered through enforcement action and returned to TfL between January and June 2025. Alex Williams, TfL’s chief customer and strategy officer, said: “With 97% of vehicles seen driving in London ULEZ compliant, only a very small minority of vehicles now don’t meet the standards. “Most drivers who have vehicles that are liable for the charge are responsible and pay it.