A fireworks and lights show has heralded the opening of a new £600m toll bridge over the River Mersey.
Expected to cost £1.9bn until 2044, the Mersey Gateway route is the largest infrastructure project in England outside London, a spokesman said.
The bridge between Runcorn and Widnes in Cheshire opened after midnight.
The government said tolls would be dropped once the costs are paid but campaigners said the charges will hit residents and local businesses.
Building work on the six-lane bridge, which is the second crossing between Runcorn and Widnes, began in 2014.
The 1.5mi (2.2km) link forms the centrepiece in a project of improvements on a 9.2km route in the borough of Halton.
The total cost of the route - including construction, maintenance and operation - is estimated to be £1.9bn until 2044, a spokesman for the Mersey Gateway Project said.
Hugh O'Connor, general manager at Merseylink, added the bridge was "opening on time and on budget" and paid tribute to those "who worked so hard to make that happen".
Officials hope it will ease congestion on the nearby Silver Jubilee Bridge while improving access to jobs and Liverpool John Lennon Airport.
However, many locals have criticised the toll's impact. Halton resident Jodie Fisher said: "Runcorn isn't a destination town, I worry we won't get that investment and it will become a ghost town."
Davina Morrell, a single mother who works in Liverpool, said: "I'm going to have to pay £700 a year to travel over the bridge. It's an awful lot of money when I'm only a nurse."
David Parr, chief executive of Halton Borough Council, said: "We had a congested bridge and the government were saying to us if you want to reduce that congestion you need to have a toll crossing - toll bridge or no bridge."
The government, which approved the project in 2006, said it had already paid £86m and will provide £288 million after the opening.
Its contribution will make up 20% of the cost while the remaining 80% is being funded by tolls, a Mersey Gateway Project spokesman said.
For whom the bridges toll
- Eligible residents in Halton can cross the Mersey Gateway Bridge and Silver Jubilee Bridge for free once they have paid a £10 annual fee
- Other drivers will have to pay tolls and must register on the official Merseyflow site to get discounts or free travel
- More than 82,000 vehicles have been registered but motorbikes and local buses will not be tolled
- Drivers can still cross both bridges without registering but will have to pay the full toll, ranging from £2 to £8 per crossing, or face a penalty of up to £60
- There will not be any toll booths as number plate recognition technology will be used to collect payments
Tolls will also be implemented on the old Silver Jubilee Bridge - known locally as the Runcorn Bridge - once it reopens next year after repairs.
It is closed to drivers for about 12 months so it can be "restored... to its original function as a local bridge with improved public transport and cycling/pedestrian provision", a Department of Transport spokesman said.
The crossing will remain open to cyclists and pedestrians during the repairs.
Campaigners against the tolls intend to hold demonstrations at Runcorn Town Hall and in Widnes on Sunday afternoon.