The London Orbital's Missing Link
The Dartford Crossing (the A282) has become one of the most strategically important parts of the road network in the UK, carrying traffic of international and national importance, as well as catering for regional and local movements. It is the only river crossing on the strategic road network to the east of London.
The Dartford Crossing (A282) is not build to modern motorway standards and therefore is a missing link, a bottleneck in the London Orbital motorway, the M25.
The crossing comprises two, two-lane tunnels northbound, and the The Queen Elizabeth II Bridge, opened in 1991 carrying four lanes of southbound traffic.
The Dartford Crossing currently (2014/15) operates at a capacity of 137,411 average vehicles per day (avpd) and in practice the crossing carries as much as 160,000 vehicles per day. This exceeds it's design capacity of 135,000 avpd. There is clearly insufficient capacity to cater for current and future traffic demand.
The southbound bridge has a fixed 50mph speed limit imposed. The northbound tunnels are aged and relatively small by modern standards, such that for safety reasons, abnormal and hazardous loads have to be escorted through them while all other traffic is held back. This is believed to be one of the primary causes of northbound congestion.
For more information please read Section 2, on page 2 of Pre-Consultation Scheme Assessment Report Volume 1: Executive Summary
Figures show the Dartford crossing has been at least part-closed once every three days in the year to March 2016.
Summary of closures (in 1 year):
Total number: 108
Number of complete closures: 1
Closures for planned construction or maintenance works: 81
Unplanned bridge closures: 9
Unplanned closures of the west tunnel: 5
Unplanned closures of the east tunnel: 12
It was also revealed that the average incident at the crossing takes 27 minutes to be dealt with, but then up to five hours for roads to then return back to normal following a build-up of traffic.