The company which operates the 27-mile toll road said it had been a "driving force" for economic growth and helped to cut congestion and pollution.
It comes just weeks after it was revealed council bosses in the West Midlands and Mayor Andy Street were considering putting pressure on M6 Toll bosses to cut charges or ditch them completely.
The toll is privately owned and run by Midland Expressway and there has been no signal as yet the company would entertain lowering rates.
Council leaders believe making the toll cheaper to use could be crucial to cutting congestion on the M6 and reducing emissions.
James Hodson, M6 Toll director for motorway operations, was speaking as the road welcomed its 250 millionth customer since opening in 2003. Public statements have been a rarity from Midland Expressway over recent years amid continued questions over the future of the toll road.
Latest figures showed revenues continued to rise during 2018 to more than £90m, though the toll road has yet to make a profit since opening because of the huge amount it is repaying in interest on the original motorway construction costs.
Traffic fell slightly by around 100,000 to 18.2m last year.
Mr Hodson said: "Since it opened in 2003 the M6 Toll has been a driving force for regional economic growth, alleviating congestion and pollution as well as helping drivers and commercial fleet operators to reach their destination on time any time.
"We are excited to celebrate the 250 millionth journey on the M6 Toll."
Mayor Andy Street said in August he would seek to convince the toll's operator to reduce prices after they went up again to £12 for lorries and £6.70 for cars. An Express & Star poll found 82 per cent of people wanted the toll road to be made free.