Work began at 6am today to remove 27 toll booths on the southern end of the Dartford Crossing.
The booths on Britain's busiest motorway are being scrapped and replaced with an electronic payment system.
The changes at the Dartford Crossing on the M25 east of London are designed to improve traffic flow.
But the removal of the 27 toll booths at the southern end of the crossing will result in roadworks until March 2015.
And car drivers using the crossing will from today face a higher daily charge - with the fee, also payable by phone or post as well as online, going up from £2 to £2.50. Charges are also rising for goods vehicles.
The Highways Agency is hoping for a minimum of congestion at the start of the new system.
An agency spokesman said: "We're starting at 6am on a Sunday when traffic will be comparatively light and there will be plenty of signs up to tell people about the new arrangement.
"Monday morning will be more of a test but we are trying to do everything we can to let people know about the changes."
Local residents who regularly use the Dartford crossing could have missed out on years of discounts. Since 2008 drivers in Thurrock and Dartford are supposed to have paid less to use the crossing.
However an investigation has found the Highways agency has failed to promote the scheme -- because of fears it will reduce the amount collect at the toll booths. Sangeeta Kandola reports.
Automated charging for motorists on the M25 has moved a step closer. The Highways Agency has awarded a contract to deliver a new 'free-flow' system for the Dartford Crossing and QE2 Bridge. It means the barriers currently being used would disappear.
- There are currently more than 24,000 people signed up to the Local Resident Discount Scheme
- 4,000 local residents make more than 100 trips each in a year
- 700 of them make more than 400 trips a year
- These residents are set to save money with the £20 flat rate
Local businessmen and women use the Dartford crossing regularly to make deliveries into Essex and Kent.
They are the backbone of British industry and that is why I am keen to find new ways we can make their lives cheaper and easier.
At a cost of just over 5p a day we will help thousands of small businesses keep their costs down as well as saving money for those who currently belong to the residents' discount scheme.
4,000 people living close to the Dartford Crossing will be given the welcome option of cheaper travel from March next year. People registered in the Local Resident Discount Scheme will be able to make unlimited trips over the crossing for £20 a year.
Police are continuing to question a man on suspicion of making a bomb hoax following claims which led to the Dartford Crossing being closed in both directions.
Kent Police said the 27-year-old foreign national had made threats of a suspicious device on board the coach he had been travelling on.
The incident led to motorists being caught in nine-mile long tailbacks after both the QE2 Bridge and Dartford Tunnels were closed for almost seven hours during rush-hour traffic on Friday night.
Releasing further information, police said they recovered a cylindrical device with wires inside a heavily sealed bag from the coach.
It was found after the force was called at 4.03pm to a report of a male pedestrian behaving unusually at the Dartford Crossing.
He had alighted from a coach which was Dover-bound and run to a rough area nearby, police said.
Security personnel at a nearby distribution depot detained the man and officers arrested him at 4.15pm before he was taken to a police station.
There he made threats as to a suspicious device on board the coach.
The vehicle, which had just gone through the toll booths, was evacuated along with the immediate surrounding area, which was extremely busy at the time.
The man also made further threats that there was an explosive device on another coach.
Officers stopped a coach at 6pm on the A20 at Dover and it was evacuated.
No threat was found and the occupants were later reunited with their coach to continue their journey.
The A20 reopened around 10.45pm.
The M25 Dartford Crossing in Kent has been re-opened after a security alert last night. Drivers were stuck for more than seven hours in nine-mile tailbacks after a pedestrian, who was spotted behaving strangely, was arrested at the scene.
The Queen Elizabeth II Bridge and both tunnels were shut when police officers found a suspicious item. But after Army bomb disposal teams investigated, they said the item posed no threat and reopened all routes.
The A20 was also closed in Dover as officers stopped a coach as part of their inquiries into the Dartford Crossing incident.The coach was removed from the scene, police said, and the road was later reopened. The arrested man remains in police custody. No further arrests were made.
Kent Police has thanked hundreds of motorists for their patience after they were stranded on the M25 following a security alert. Police have now confirmed a suspicious package is not a threat and are reopening the crossing.
UPDATE: Dartford Crossing being reopened now. Thanks everyone for your patience.
Kent Police has tonight said "the item ofinterest does not pose a threat. Enquiries have concluded on the scene and TheHighways Agency and Kent Police are in the process of reopening the DartfordRiver Crossing."
The A20 in Dover has been fully reopened after a search of a coach. No items have been found and enquiries continue. The coach has been removed from the scene and no further arrests have been made."
A man arrested from the Dartford River Crossing today remains in police custody.