Northbound tunnels at Dartford on the M25 to close for emergency response exercise.
United Kingdom – The northbound tunnels at the Dartford-Thurrock Crossing on the M25 will close on Sunday June 11th to make way for a full emergency response exercise.

The closure, on the UK’s busiest motorway, will take place between 01:00 BST and 06:00 BST to minimise disruption for some 2,500 drivers.

"It is vital to ensure that in the case of a real emergency all the parties involved operate in an efficient manner to safeguard the public, as well as guaranteeing the minimum disruption to traffic flow," said John Aspinall, Highways Agency divisional director for the south-east.

"Holding Exercise Orpheus means that the authorities’ response to a real emergency would be swift and practiced."

Northbound traffic will be diverted while southbound traffic will be unaffected.

The 27-mile (43km) diversion runs from Junction 2 of the M25 on to the A2, through the Blackwall Tunnel, the A102 and on to the A13 back to Junction 30 of the M25.

Due to the four-metre height and hazardous goods restrictions at the Blackwall Tunnel, some vehicles will need to use the alternative route for northbound traffic and travel clockwise around the M25.

The exercise will test responses to major incidents in the tunnels, helping to train emergency personnel for such eventualities and potentially reducing disruption for drivers if an incident was to actually occur.