Smart Motorway Signs: Lane Closures and Obstructions

When smart motorways work as intended, Highways England are able to respond in real-time to traffic flow, obstacles in the road, collisions, breakdowns and other incidents. This is called active traffic management, and works using a system on cameras to detect potential or existing problems. Traffic control centres can then update smart motorway signs for drivers to follow, helping to keep everything running smoothly and safely.

Types of smart motorway signs

You’ll find some smart motorway signs at the side of the road, just as you would on any route. But there will also be regular gantries—bridge-like structures above the road—which can give you specific information relevant to your lane, such as whether it is open or closed, and any changes to the speed limit.

There are also message boards, which show further information about the road ahead. 

Red X signs

A red ‘X’ sign above any lane indicates that it is closed; traffic in that lane should divert to another lane to avoid coming across an accident, broken-down vehicle, roadworks or some other hazard in the road. There won’t be a physical barrier preventing you from staying in that lane, or moving across into it—and it might not be immediately obvious why the lane is closed. But, however tempting it is to ignore the sign and beat other traffic, it could well cost you.

Disobeying a red X is an offence punishable by:

• Three points on your licence 
• Up to £100 fine
• Compromised safety of yourself and other road users 

Instead, as soon as you see a red X on a gantry, check your mirrors and blind spot and move lanes if necessary. Stay alert: other vehicles will be changing lanes too.

And finally, keep an eye out for signs above the other lanes. Chances are that variable speed limits will kick in and you’ll have to go slower until you’re past the hazard. 

Arrow signs

If there is an upcoming obstruction in one lane, you may also see an arrow pointing you to move left or right. This is often to give you advanced warning that the lane is going to be closing; getting out of the lane at this point helps ease congestion further ahead. 

Other arrows pointing onwards (straight ahead) indicate that the corresponding lane is open. 

Variable speed limit signs

Usually, UK motorways enforce a speed limit of 70mph for cars—the national speed limit for any dual carriageway. Any deviation from this will be indicated by speed limit signs. These can be temporary, in the case of roadworks, or more permanent, in areas where accident reduction schemes are operating. 

Smart motorways work in a similar way: unless otherwise indicated, you can drive at 70mph. But because they feature technology that is much more responsive to live events, speed limits are variable: they can be changed almost immediately to counteract the effects of congestion and incidents such as breakdowns, roadworks or collisions. The variable speed limit signs are displayed on the gantry above the lanes they affect (usually all of them) or on a display board at the side of the road.

Any speed limit displayed in a red ring is legally enforceable, whether it's variable or not. That means ignoring the instruction can land you with points and a fine, or a speed awareness course, depending on your eligibility. Some motorists may also be disqualified from driving for a period of time.

If there is a speed camera positioned just after a variable limit comes into effect, drivers may be afforded a grace period. But that’s only to give you time to slow down safely, and not something to rely on. 

How much could I expect to pay for a speeding fine?

Fines start at £100, but can rise to a maximum of £2500 on motorways. If you’re successfully prosecuted in court, the amount you pay is based on your weekly income, or—if you’re unemployed—factors such as your financial situation and earning potential. It also depends on the speed limit, how significantly above it you were travelling and whether you’re a repeat offender. 

Any points you accrue will stay on your licence for four years. Remember, if you’re a new driver, six points (or two ‘minor’ speeding offences) will see you lose your current licence for good. You’ll have to apply for a new provisional, then retake your theory and practical tests to get back on the roads. 

What's the point of variable speed limits?

The aim of variable speed limits is to keep you moving. Slowing all vehicles down by 10 or 20 miles an hour is often enough to prevent tailbacks and frustrating queues of stop-start traffic. However, this does cause confusion for some drivers, who don’t understand why they’re being told to decrease their speed when traffic appears to be flowing. Consequently, you might see others on the road ignoring the rules and continuing to drive at 70.

Emergency Refuge Area signs on smart motorways

On smart motorways, some of which have no permanent hard shoulder, Emergency Refuge Areas (ERAs) act as spaces designed for broken down vehicles or those that have been involved in an accident. They are for emergencies only, and you should never use one simply to swap drivers, take a break, go to the toilet or use your phone. You should find one at least every mile and a half along the road—and more are now being added, following safety concerns. 

ERAs can be identified by blue rectangular signs featuring the SOS telephone symbol in orange. The tarmac itself is often painted orange as well, to help it stand out, and will look rather like a lay-by. 

How do I use an ERA?

Once you have safely pulled into the ERA, stop your vehicle, activate your hazard warning lights, then get out of the car using nearside doors (those on the left hand side), away from moving traffic. For most vehicles in the UK, this means the driver should exit through the passenger door. Get yourself and any passengers behind the crash barrier, if there is one, and behind and away from your vehicle.

If you’re able to, you should also use the SOS phone to speak to a representative from Highways England—even if you have already informed another party, such as your breakdown service provider, of your position. Highways England can close the left hand lane of the motorway—using a red X sign—and slow other traffic down with variable speed limit signs, to keep you as safe as possible. They will also be able to advise you on what to do next. 

If you’re stuck inside your car, keep your seatbelt on and call 999 instead. 

What should I do if I can’t make it to an emergency refuge area?

Try to move to the left hand lane, and onto the verge if that’s a safe option. Set your hazard lights blinking, and—if there’s space for you to wait more safely, get out using the left hand doors. 

Always keep your seatbelt on if you have to remain in your vehicle.

Message signs on smart motorways

Sometimes symbols aren’t enough to convey the information drivers may need. Enter: message signs. These are large, electronic displays, often situated at the edge of the road or on gantries, where text can warn motorists of up-to-date details on weather and road conditions, the likelihood of queues ahead, alternative route options or reports of debris in the road. 

This information is less about rules, and more about helping drivers make appropriate choices, manage expectations and modify their behaviour. 

Not all of the information on smart motorway message signs will be relevant to every motorist. For example, sometimes there will be a specific message aimed at HGV drivers, or those hoping to take a certain exit. But it’s important to get into the habit of reading them, so you know what’s going on.

Benefits of smart motorway signs

The beauty of smart motorway signs is the speed at which they can be updated. That means that traffic is more rarely queued, drivers are better informed of upcoming incidents and speeds can be changed gradually, reducing the need for sharp braking.

But gantry signs on motorways don’t just afford drivers a more pleasant experience: they also create safer roads. Data from May 2022 reveals that between 2016 and 2020, all types of smart motorways were safer than other motorways and A roads included in the strategic road network (SRN). And, crucially, fewer collisions resulted in serious injury or loss of life.

Those statistics don’t yet reflect any effect of more recent safety measures, such as retrofitting more ERAs or campaigns to increase driver awareness about how to use smart motorways. Hopefully these steps will continue to improve their functionality and safety.

Concerns and criticisms

There have been several tragedies since the introduction of smart motorways, most prominently in instances where one vehicle was already stationary (for example after it had broken down). This led the government to pause the rollout of all-lane running smart motorways—where the default position of the hard shoulder is that it’s open for all traffic—until more data can be gathered. 

There is also still a tendency for some drivers to ignore smart motorway signs, such as red X’s or variable speed limit signs. This makes it less safe for everyone. However, as the public becomes better informed, this should become less of a problem.

Smart Motorway Signs FAQs

What are the different types of smart motorways?

There are three different types of smart motorway.

• All-lane running (ALR) motorways are the most controversial, as drivers can make use of the hard shoulder at any time—except when there's an obstruction and a red X sign prevents it. 
• Dynamic hard shoulder (DHS) motorways allow motorists to use the hard shoulder to ease congestion during busy periods. The red X will be used when it's operating as a normal hard shoulder.
• Controlled motorways keep the hard shoulder as normal, but are still able to employ variable speed limits to keep traffic on the move.

Are smart motorway speed cameras always on?

As with any speed camera, the best thing to do is to assume it's always on. Cameras can be set to catch set anyone going above the variable speed limit—but where one isn't in effect, they will revert back to monitoring the national speed limit. 

Enforcement cameras can also detect vehicles driving in closed lanes.