What is a smart highway? UK motorway map, how safe is it and why has implementation been delayed

Martin Woolridge 3 years ago 3 min read

What are smart highways?

Smart highways are expressways that use technology to regulate the flow of traffic.

There are three main types:

review Have a permanent shoulder like regular highways, but use technology such as adjustable speed limits, indicated by overhead signs, to regulate the flow of traffic
Moving The hard shoulder can be converted into another lane for traffic during peak hours, with the speed limit reduced to 60 mph. The top marks will show an X on the shoulder if closed
Run all the lanes – The hard shoulder is permanently another lane for traffic, with emergency shelter areas (mainly siding) at regular intervals (currently every 2.5 km) that drivers can use in an emergency

In addition to informing drivers of speed limits, which are regulated by speed cameras, overhead signs can also alert people to accidents or other dangers at a later time.

Where are they in the UK?

Most of the UK’s smart motorways are located around London, the West Midlands and the North West.

There are approximately 375 miles of smart highways currently in operation, 235 of which are shoulderless.

A map of the UK’s current smart highways (Map: Highways England)

Most of the M25 is now a smart motorway, as are the long stretches of the M1.

There are also smart motorway sections on the M3, M4, M5, M6, M20, M23, M27, M40, M42, M56, M60 and M62.

Another 100 miles of the smart highway currently under construction for all lanes will be completed, while 57 miles of planned roads will be suspended.

This includes work on the M3 between Junctions 9 and 14, the M40/M42, and M62 interchange between Junctions 20 and 25 and the M25 between Junctions 10 and 16.

The government said that on roads currently under construction, emergency shelter areas should be separated by no more than 1.5 HK, ideally 1 kilometer apart.

Why could they be dangerous?

A review published in November found that there was not enough safety and economic data to justify building more multi-lane highways today.

Now another five years of data will be collected for these types of tracks, which will remain open for the time being.

The lack of a standing shoulder prompted critics to say drivers can get stuck in fast traffic during emergencies.

Government figures show that 38 people died on smart highways between 2014 and 2019.

Transport Secretary Grant Shapps said: “While our initial data shows that smart motorways are among the safest in the UK, it is critical that we do everything we can to ensure people feel safe using them.”

But activist Claire Mercer, whose husband Jason was killed on a smart stretch of highway near Sheffield in 2019, said. BBC News:: “The only acceptable thing is to bring the shoulders back permanently, 24/7, on all highways.”