The contract includes operating the system for up to 10 years.
Instead of stopping at barriers, drivers will be able to pay through a variety of methods including telephone, text, online and in shops. Pre-paid accounts which qualify for discounted journeys will also be available.
The aim is to reduce congestion. The crossing carries the M25 London orbital motorway on the east side in two tunnels (northbound) and over the Queen Elizabeth II bridge (southbound). There are often long queues for the toll booths.
Highways Agency project manager Nigel Gray said: “We are introducing new technology and road layout changes to change the way drivers pay to use the crossing. Once it is fully implemented drivers will not have to stop at the barriers, but will pay for their journey remotely. This will reduce congestion and ease traffic flow. The contract covers the development as well as the ongoing operation of the new payment system. We remain on track to deliver this improvement in October 2014.”
Sanef stands for Société des Autoroutes du Nord et de l'Est de la France.