Dartford Crossing: Both Tunnels Shut 8pm Tonight

Both northbound tunnels at the Dartford Crossing close tonight at 8pm. They are due to reopen at 5am on Sunday.

Nothing goes under the river in that window. A temporary contraflow will run across the QEII Bridge instead, with one lane in each direction. National Highways updated its A282 Dartford Crossing maintenance page with the arrangements on 11 September.

The reason is not maintenance. It is “a planned exercise to test emergency procedures at the A282 Dartford-Thurrock River Crossing”, in National Highways’ words, and it needs both bores empty for one night.

What is closed, and the diversions

Three slip roads shut alongside the tunnels, to keep the contraflow safe:

• the A282 junction 1a northbound entry slip, diverted to M25 junction 2 and back
• the A282 junction 1b northbound entry slip, diverted to M25 junction 2 and back
• the M25 junction 31 southbound entry slip, diverted to junction 30 and back

That means no northbound joining at Dartford itself, and no southbound joining at Thurrock, for the length of the closure.

Expect blue lights without an incident behind them. “You may notice an increased presence of emergency service vehicles and personnel at the crossing,” National Highways says. “This is a planned exercise designed to help us ensure our emergency response procedures remain effective.”

The times have moved since last weekend

National Highways’ seven-day closure report, published at 3.32pm on 7 September, had the two bores shutting separately. The east tunnel was listed from 8.30pm, the west from 10pm, both until 6am.

The A282 page updated on 11 September gives a single window instead: 8pm to 5am, both tunnels. It is the newer of the two, and the only one that sets out the contraflow and the slip road diversions, so it is the one we have followed. The closure report’s own search tool returned nothing for the A282 when we tried it on 12 September, so we could not re-read it today.

Either way, 8pm is the time to be clear of the tunnels. Our Dartford roadworks and travel page has been updated to match, with a dated note explaining the change.

If you cross before 10pm, you still pay

The Dart Charge applies “between 6am and 10pm, including at weekends and on bank holidays”, GOV.UK states. The closure starts at 8pm, so the first two hours of it fall inside charging hours. Crossing on the contraflow is still crossing. Payment is due “by midnight the day after you cross”.

Dartford and Thurrock residents can cap their charges with a local resident discount scheme, which is worth checking if you are being pushed onto the crossing by these closures. We covered how much the crossing now takes in penalties in Dartford Crossing fines now out-earn the toll.

Lorry drivers: the marshalling rules change, then change back

While the contraflow is running, dangerous goods vehicles and abnormal loads “will not need to report to the marshalling area on the Kent side of the crossing”. Traffic management and signs will send every vehicle over the bridge instead.

Once the contraflow is lifted, the normal rules resume. Those vehicles must report to the Kent-side marshalling area again, and anything needing an escort is escorted through the tunnels as usual.

Why the crossing shuts as often as it does

The Dartford Crossing was designed to carry 135,000 vehicles a day. National Highways puts the current average at 150,000, with the busiest days reaching 180,000, and more than 50 million vehicles a year in total. Almost 40% of them are lorries or other freight vehicles.

The figure that explains the queues is not the traffic count, though. It is the closure count. One of the tunnels shuts “on average every 15 minutes during peak times”, National Highways says, and “this adds up to around 27 days per year”. (National Highways, The Dartford Crossing)

Most of those stoppages last minutes. An over-height lorry, a breakdown, a spillage: the tunnel holds traffic, the problem is cleared, the queue unwinds. Added together they cost the equivalent of nearly a month of the crossing every year, on a route already carrying 15,000 vehicles a day more than it was built for.

Separately, the QEII Bridge has been having its cable stays refurbished since April, with overnight lane closures from 9pm to 6am and at least one lane kept open. There are 112 cable stays in 56 pairs. National Highways aims to finish 53 this year and the remaining 56 in 2027.

The rest of September, night by night

From the same page, updated 11 September:

Next Saturday is the one to diarise. The QEII Bridge closure on 19 September is listed as 9pm to 9am, a twelve-hour window that runs well into Sunday morning.

National Highways warns that “closures can change at short notice”, which this week has already demonstrated.

What we could not confirm

The crossing also closed unexpectedly on the evening of Thursday 11 September, and queues built back along the M25. We are not reporting a cause for that, because no first-party account of it has been published.

Kent Police and Essex Police have each issued no statement about it on their own news pages. National Highways’ travel alerts page carried no alert for the A282 when we checked on 12 September, and the A282 project page does not mention the incident. If a force or National Highways publishes an account, we will add it here.

What it means for you

• Tonight, 8pm to 5am: if you are heading north, allow for the contraflow. One lane each way across a bridge is a fraction of the capacity of two tunnels plus four bridge lanes.
• Joining the crossing: you cannot join northbound at A282 junctions 1a or 1b, or southbound at M25 junction 31. Use M25 junction 2 from the Kent side and junction 30 from the Essex side.
• Late trains are an alternative going into London, not across the river here. Our Dartford train times to London page has the last services.
• Pay the Dart Charge if you cross before 10pm. The closure does not suspend it.
• Check before you set off. Closures move. The National Highways closure report is the source we check, and our roadworks and travel page carries the week at a glance.