Motorists evading paying tolls on the Auckland Northern Gateway face a crackdown by the Transport Agency.
The agency has identified five drivers who owe the most - nearly $10,000 collectively - and will prosecute them.
National toll manager Andy Thackwray said paperwork was being drawn up to get prosecutions under way in the next three to four months.
Four of the five top fine evaders came from Auckland, the fifth was from Northland. Collectively the motorists owed a combined $9420 in unpaid tolls and administration charges.
After three years of the 7km-long section of State Highway 1 being open, there was a compliance rate of 96 per cent of motorists paying the toll, Mr Thackwray said.