Around 1,200 closures of the vital Blackwall Tunnel River Thames crossing last year were caused by over-height vehicles and lack of fuel.

The unplanned closures cost more than 13 days of “serious and severe traffic congestion” both north and south of the river which meant added police enforcement.

Figures from TfL show that in the last nine months, the Blackwall Tunnel has had to be closed 1,604 times, 70 per cent due to drivers ignoring the height restriction warning signs throughout the Northbound tunnel while vehicle break-downs were responsible for 287 closures; a third of which were simply due to vehicles running out of fuel.

Although the tunnel closures are often for only a few minutes, the resulting queues and traffic congestion can last for hours.

TfL has begun a three month trial which will see a team of roads response police officers based at the Blackwall Tunnel to provide an immediate response to any unplanned incidents, like breakdowns.

A new digital sign has been installed on the northbound approach, highlighting the number of over-height and broken down vehicles that have stopped traffic in the last month.

Kulveer Ranger, the Mayor’s transport advisor, said: “We all know how frustrating it is sitting in traffic, even more so when the reason for the jam is so easily avoided. We are asking all drivers using the Blackwall Tunnel to use their common sense and make sure their vehicle is not too high to get through and is not likely to break down or run out of fuel in the tunnel. It sounds simple but these sorts of problems are causing thousands of drivers to sit in pointless traffic jams for hours on end.”