Smart motorways use variable speed limits and hard shoulder running to manage traffic and tackle stop-start congestion.

The most common type in the UK, all-lane-running (ALR), was introduced in 2014 and involves opening the hard shoulder permanently to drivers.

Gantry signs displaying a Red X indicate if a lane is closed – usually as a result of a vehicle breakdown or in the event of a collision.

Driving through a Red X sign is an offence, the punishment for which is three points plus a £100 fine. Since 2019, police forces have been able to use traffic cameras by means of enforcement.

The campaign, which runs until 26 February, is aimed at all motorists that use the strategic road network. 

One of the primary aims is to increase understanding of the rules, fines and how automated enforcement works.

This is being achieved through the use of radio and social media (Facebook, Twitter, Reddit and LinkedIn) – as well as out of home media, including large digital posters and posters in motorway washrooms.

These activities point towards a campaign webpage, where road users can find a series of illustrations showing a typical sequence of signs and signals they’ll see on the motorway when a Red X signal is set.

The page reads: “Have you noticed the Red X signal when driving on motorways?

“It’s there for your safety and it’s illegal to ignore it.

“The Red X sign is key to supporting safety on motorways. It tells you when a lane is closed, helping any drivers and their passengers who may have got into difficulty. It also provides a safe place to work for the emergency services, recovery operators and our road workers.

“Most drivers respect the Red X signal. But those who don’t put themselves and other road users at real risk.”