Queen Elizabeth II Bridge

Queen Elizabeth II Bridge. It is a major cable-stayed bridge that carries the M25 motorway across the River Thames between Dartford in Kent and Thurrock in Essex. Opened in 1991 by Queen Elizabeth II, it forms the final component of the orbital motorway's crossing at the Dartford Crossing, working in conjunction with two adjacent tunnels. The structure is a critical piece of national infrastructure, handling a significant portion of road freight and passenger traffic between London and key ports like Dover and Felixstowe.

History and Construction

Planning for an additional Thames crossing at Dartford intensified in the 1980s due to chronic congestion at the existing tunnels, which were struggling with the volume of traffic on the expanding M25 motorway. The Department for Transport approved the bridge scheme, and construction was awarded to a consortium led by the German firm Hochtief and the British Kier Group. Work began in 1988, with the project managed by Travers Morgan and supervised by the Kent County Council and Essex County Council. The bridge was officially opened on 30 October 1991 by Queen Elizabeth II, completing the orbital motorway and providing much-needed relief for one of Europe's busiest road junctions. The total cost of the project was approximately £120 million.

Design and Engineering

The structure is a classic example of a modern cable-stayed bridge design, chosen for its efficiency and aesthetic appeal over such a wide crossing. Its main span measures 450 metres, with an overall length of 812 metres, and it rises to a height of 137 metres at its twin H-pylons. The deck, constructed from steel and concrete, is supported by a complex array of stay cables anchored to the pylons. The design was developed by the engineering firm Hellmut Homberg and required innovative construction techniques, including the use of a cantilever method to build out from each pier. Its design allows for the necessary clearance for shipping on the busy River Thames, accommodating vessels heading to ports like the Port of London and Tilbury.

Operation and Traffic

Operated by Connect Plus under a private finance initiative contract for Highways England, it functions exclusively as a northbound route, while the two older tunnels carry southbound traffic, together forming the Dartford Crossing. It is a vital link in the UK's strategic road network, connecting the A282 road and facilitating international trade routes from the Channel Tunnel and Dover. Traffic levels frequently exceed design capacity, often surpassing 160,000 vehicles daily, making it one of the busiest estuarial crossings in the country. The crossing is subject to a Dart Charge electronic tolling system, managed by Sanef, to maintain traffic flow.

Tolls and Financing

The crossing was originally financed through a Build-Operate-Transfer scheme with the private consortium Le Crossing, with tolls implemented to repay construction costs. Tolls were controversially maintained after the initial debt was cleared, with revenue now directed to the Department for Transport for general transport expenditure. The old toll booths were removed in 2014, replaced by an entirely electronic Dart Charge system operated by Sanef. Charges apply for all motor vehicles, with higher rates for HGVs, and are enforced using Automatic Number Plate Recognition cameras linked to the Driver and Vehicle Licensing Agency.

Incidents and Closures

The bridge is highly sensitive to high winds, leading to frequent speed restrictions and occasional full closures to high-sided vehicles during storms to prevent accidents. A major incident occurred in 2020 when a lorry fire caused a complete shutdown for several hours, creating severe delays on the M25 motorway and surrounding routes like the A13 road. It has also been closed for security alerts and for planned maintenance operations conducted by Connect Plus. Such closures have a significant economic impact, disrupting supply chains to major distribution hubs in the East of England and causing congestion throughout the South East road network.

Category:Bridges in Kent Category:Bridges across the River Thames Category:M25 motorway Category:Buildings and structures completed in 1991