Dartford Crossing fines up to £105 when barriers removed
Drivers will be fined up to £105 for failing to pay the toll at the Dartford Crossing over the River Thames under a new electronic charging system.
The Department for Transport plans to remove the existing barriers by autumn 2014, allowing people to pay by phone, text, online or in shops.
The "free-flow" system is designed to speed up traffic and ease congestion at the crossing between Kent and Essex.
The toll for cars increased by 50p to £2 from 7 October.
The Highways Agency said once the toll barriers were removed and free-flow technology installed, road users would be able to pay at the standard rate up to midnight or at the standard rate plus 20% the following day.
Prof Stephen Glaister, director of the RAC Foundation, said: "This is progress. Free-flow tolling cannot come soon enough.
'Traffic will improve'
"The crossings are just about the most congested part of the national road network and given that toll charges are rising, the least drivers should be able to expect is an unimpeded journey."
The penalty for non-payment will be £70, reduced to £35 if it is paid within 14 days. Over 28 days, the penalty will increase to £105.
"By removing the barriers congestion will be reduced and traffic flow will improve, but that means the way payment is collected will change," said roads minister Stephen Hammond.
"We need to make sure we have steps in place to allow enforcement against drivers who do not pay."
The toll for the crossing has increased to £2.50 for two axle goods vehicles. It went up by £1.30 for heavy goods vehicles to £5.
It is free for motorcyclists, while local residents and account holders who pay in advance get a discount.
Two public consultations on the free-flow proposals begin on Monday.