what are smart motorways & how do they work?

What are smart motorways?

A smart motorway is an area of motorway that is controlled by active traffic management (ATM) technology that aims to reduce congestion and increase motorway capacity in particularly busy areas. They can be identified by the absence of a hard shoulder, as well as variable speed limits and other information displayed on digital screens on the gantries overhead. There are three main types of smart motorway:

Controlled Motorway (CM)

 Controlled motorways maintain the traditional layout of three or more lanes with a hard shoulder, which should only be used in the case of a genuine emergency.

The mandatory speed limit is also displayed on the overhead signs, although it is subject to change depending on the traffic conditions. Therefore, drivers must be mindful and responsive to any speed limit changes at all times. If there is no speed limit displayed, then the national limit applies. CCTV and speed cameras are used along smart motorways to enforce speed limits. Highways England has confirmed that the speed cameras are deliberately updated with the new speed limit slightly after drivers are, in order to allow people to slow down safely without slamming on the brakes to slow down in time.

All Lanes Running (ALR)

An all lanes running scheme entails the use of the hard shoulder as an additional lane for cars to use normally. The only time the hard shoulder (or ‘first lane’) is closed off is when there has been an incident in which case, a red ‘X’ is displayed on the gantry sign overhead indicating that all vehicles must move out of that lane immediately. Failure to do is extremely dangerous and can result in points on your license and a fine.

All lane running motorways have Emergency Refuge Areas (ERAs) at the side of the road in the event of an emergency, that are spaced approximately 1.5 miles apart.

Like a Controlled Motorway, variable mandatory speed limits are displayed overhead.

Dynamic Hard Shoulder (DHS)

Dynamic hard shoulder running schemes make use of the hard shoulder as a normal running lane during particularly busy times but in normal circumstances, keeps it reserved for emergencies and incidents. A single white line is used to distinguish the hard shoulder from the carriageway and overhead signs will indicate whether it is open for normal traffic to use.

Like the other two types of smart motorway, variable speed limits are displayed overhead, speed cameras are in use and a red ‘X’ means that that lane is shut to normal traffic.

How much safer are smart motorways?

 Smart motorways have received a mixture of responses since the very first one was implemented on the M42 in the West Midlands in 2006. Whilst their main purpose is to control traffic, improve the flow of vehicles and overall road safety, many people have said that the absence of a hard should actually makes them much more dangerous, particularly in the event of an emergency. In response to the criticism, Highways England has asserted that smart motorways have

• Improved journey reliability by 22%
• Reduced the number of personal injury accidents by over 50%
• Severity of accidents when they did occur is much reduced with no fatalities and fewer serious injuries.

The future of smart motorways

 Smart motorways are still being developed all the time, as constant advancements in technology enable improvements to the once basic system to be made. One major plan involves the use of sophisticated 5G broadband that will run through fibre optic cables along busy motorways between major cities such as London, Bristol, Leeds and Manchester. This 5G broadband will send real-time traffic updates straight to driver’s phones, including information about road diversions, heavy congestion and any accidents causing obstructions. There are even suggestions that this technology will be able to ‘predict’ heavy traffic and provide alternative route suggestions in real time (although to what degree it will accurately be able to do this is yet to be determined).

There are some plans to bring in drones on smart motorways, which could help to detect and send information about heavy traffic and potholes to the National Roads Telecommunications Service.

In Merseyside, an initiative involving smart LED road studs has already been implemented at one of the country’s busiest and most dangerous motorway junctions. Like normal cat eyes but with smart technology, these studs are synchronised with the nearest traffic lights and will turn off when the lights turn red, indicating for vehicles to prepare to stop.

All the smart motorways currently operating in the UK are as follows: