How do smart motorways work?

On By George Poland
How do smart motorways work?

Smart motorways have been a contentious topic in recent years amongst people in the automotive industry.

In light of the recent suspension on all new smart motorway projects until 2025, we take a look at what smart motorways are and how they work.

 

What is a smart motorway?

A smart motorway uses technology and procedures to manage traffic flow down busy sections of a motorway. In theory, these types of motorways are able to increase road capacity whilst also easing congestion.

Variable speed limits and the use of the hard shoulder are the main methods in which smart motorways are able to improve traffic flow, this is especially useful during rush hours.

A smart motorway can adjust the speed limits through the use of cameras either positioned on the overhead gantry or on a pole at the side of the road. Controlling the speed of cars at different sections of the motorway helps to prevent vehicles from bunching up into standstill traffic, otherwise known as phantom traffic jams.

They are also able to detect stationary cars through CCTV cameras and a Motorway Incident Detection and Automatic Signalling (MIDAS) system.

Even better than this, stationary vehicle detection (SVD) technology can pick up a broken down vehicle up to 16 minutes faster than a standard camera-based system. However, SVD is currently only available on a few smart motorways.

 

What are the benefits?

Easing traffic congestion has many benefits. Quicker travel times allow for increased productivity and a reduction in stand-still traffic is better for the environment. Making the most of the road capacity also negates the need to spend money on building extra motorway lanes.

The overhead signs are also able to shut lanes if there are any broken-down vehicles and can alert drivers of upcoming hazards.

If built correctly, smart motorways can reduce emissions, lower costs, improve safety and allow for faster travel times.

 

 

Smart motorway history

The first UK smart motorway was in operation on the M42 near Birmingham in 2006. This pilot programme was the first to test systems like Motorway Incident Detection and Automatic Signalling (MIDAS) as well as strategies such as the part-time use of the hard shoulder. 

The Highway Agency named the scheme Active Traffic Management (ATM) and would go on to construct more ATMs across the country until its name changed to smart motorways in 2013. Some smart motorways began to open up hard shoulders permanently which brought on concerns around safety. 

 

Types of smart motorway

Currently, there are three types of smart motorways. This includes 'controlled', 'dynamic hard shoulder' and 'all lane running'.

Controlled motorway – This has at least three active lanes with variable speed limits and a hard shoulder that is only open for emergency use.

Dynamic hard shoulder – This is the same as a controlled motorway but the hard shoulder can be opened up as an extra lane during particularly busy times.

Overhead signs will inform drivers of this and a solid white line will mark the left-most lane.

All lane running – This type of smart motorway has no hard shoulder in an attempt to maximise all of the lanes. Instead, emergency refuge areas (ERA) are located along the motorway every few kilometres.

There’s a dotted white line separating all of the lanes and the overhead signs will display a red cross if any of the lanes are out of action.

 

What is an Emergency Refuge Area (ERA)?

An ERA, sometimes referred to as an SOS area, is a place on the smart motorway that is designed to keep stranded vehicles safe if they break down when there is no hard shoulder available.

These locations are often painted orange for extra visibility and appear roughly every 1.5 miles on an all lane running smart motorway. Highways England are looking to increase the number of ERAs on existing and future smart motorway projects.

Drivers should always exit their vehicle if they break down, even if they don’t make it to an ERA. All occupants should stand behind the crash barrier and use the SOS telephone to speak to representatives of Highways England.

 

What fines could I receive?

It goes without saying that the rules of the road still apply for smart motorways but there are a few things that are worth noting.

Smart motorways have lots of cameras and changing speed limits, which makes it more likely that motorists will get caught speeding.

If no speed limit is displayed on the overhead screen, then the national speed limit applies, but be aware that the cameras that enforce the adjusted speeds are still active even when no speed is displayed.

Ignoring the red X that indicates a closed lane could land you with a £100 fine and three penalty points. These lanes are often closed due to maintenance or because there is a broken down car ahead, so driving in these areas can be very dangerous.

 

What are the problems?

The issues surrounding smart motorways all relate to safety, this is directed particularly at all lane running motorways where there are no hard shoulders. This means that if there isn't an ERA nearby, motorists can get caught up in the middle of fast-moving traffic. 

Data on these types of motorways is still relatively sparse. Amid the recent suspension of any new smart motorway projects until at least 2025, the transport secretary, Grant Shapps commented: “While our initial data shows that smart motorways are among the safest roads in the UK, it’s crucial that we go further to ensure people feel safer using them.

“Pausing schemes yet to start construction and making multimillion-pound improvements to existing schemes will give drivers confidence and provide the data we need to inform our next steps.”

Despite the innovation that smart motorways can provide, there remains scepticism amongst some motoring groups and MPs. However, constantly improving technology and increased spending on smart motorways from the government indicates that these types of motorways are here to stay and will be an important part of the UK's expanding road network in the future.