Up to 8,000 drivers a day are failing to pay the Dartford Crossing tolls since the barriers were done away with a month ago.
A new electronic scheme is now in operation with 85% paying the £2.50 charge for cars. It is similar to Congestion Charging in London.
The first penalty notices have just been sent out but initially offenders will have two weeks to pay the charge before they are fined.
Meanwhile the Highways Agency say there have been big savings in journey times with many trips on average speeded up by nine minutes.
There is still work needed to remove barriers and it is expected to be complete in the Spring.
Our transport correspondent Mike Pearse speaks to Nigel Gray from the Highways Agency.
One million vehicles are now registered to Dart Charge accounts with journey times significantly quicker, according to the Highways Agency.
Dart Charge, which is designed to speed up journey times at one of the UK’s busiest transport gateways, now allows drivers to use the crossing without having to pay the charge at a barrier.
Early data suggests drivers are already experiencing significant improvements, with average journey times between 7am and 7pm cut by more than 9 minutes southbound, and more than 4 minutes northbound when comparing the first two weeks of December and the end of November.
Around two million crossings have been made during the 6am-10pm chargeable period, and early indications show that to date around 85% of crossings have been paid for.
Two lanes are closed and there is slow traffic due to broken down lorry on the M25 Dartford Tunnel anticlockwise at A282 (Dartford Tunnel tolls).
The West Tunnel is closed, but the slightly higher East Tunnel remains open.
Today marks the 50th anniversary of the opening of the first tunnel at the Dartford Crossing between Kent and Essex. What is now the west bore of the current tunnel opened at midday on 18 November, 1963.
Capacity at the crossing was later increased with the opening of the east bore in 1981 and the Queen Elizabeth II bridge in 1991. The Highways Agency says the crossing is a vital transport link, continuing to bring benefits to the economy, nationally as well as regionally.
Two lanes closed at on M25 anticlockwise at the A282 (Dartford Tunnel), and there is queueing traffic after an accident involving a car and a lorry. There is congestion to J1b A282 / A296 Princes Road (Dartford).
The West tunnel is closed because of an accident just before the tunnel entrance, all traffic is going through the East tunnel.
There is queueing traffic and a lane is closed on the exit slip road on the M25 anticlockwise at J31 A1306 Arterial Road (West Thurrock) after an accident.
There is congestion on the M25 Dartford Tunnel to the J2 A2 (Darenth Interchange). The accident is just after the tunnel, on the exit slip road at J31.
A Californian King Snake has been rescued from the hard shoulder near the Dartford Tunnel. The reptile was spotted in a small plastic tank at the side of the road. The non-venomous reptile is now being cared for by snake experts.
The public are being advised to avoid the Dartford Tunnel at present if they can, after an incident which led to the closure of two lanes just after 11am.
There is queueing traffic on the M25 anticlockwise at A282 (Dartford Tunnel toll booths), and congestion on M25 to J1b A282 / A296 Princes Road (Dartford).
Kent Police are investigating the incident on the QE2 Bridge. Traffic is now using the Dartford Tunnels, but traffic is only running in two lanes in each direction.
Two lanes are closed and there is queueing traffic due to a police incident on the M25 anticlockwise at A282 (Dartford Tunnel toll booths), congestion on M25 to J1b A282 / A296 Princes Road (Dartford).
All traffic was stopped in both directions just after 11:00 due to Police investigations on the QE2 Bridge. Traffic is now using the Dartford Tunnels, running two lanes in each direction.