M20 junctions 3 to 5: smart motorway

We’ve upgraded the M20 between junctions 3 and 5 to a smart motorway. This means there is extra capacity in each direction and new technology that helps improve the flow of traffic.

Start date July 2018
End date March 2020
Cost £92 million

Latest updates

  • 13 May 2020

    Construction work complete between junctions 3 and 5

    Construction work between junctions 3 and 5 is now complete and from today this section will operate as a smart motorway.

    This means there is extra capacity in each direction and technology which will help improve the flow of traffic.

    Earlier in 2020 the Secretary of State for Transport announced an action plan for smart motorways and Highways England is taking forward the measures set out in that plan. For the M20 that work includes the roll-out of stopped vehicle detection technology within the next 36 months. Until then there will be extra traffic officer patrols on this stretch of the motorway and extra communication to help drivers.

Project information


Smart motorways use the latest technology to sense traffic flow and set speed limits. This keeps traffic moving smoothly and prevents queues of traffic. The smart motorway design for the M20 between junctions 3 and 5 involved converting most of the hard shoulder into a traffic lane to create extra capacity. More gantries with electronic information signs, signals and CCTV cameras were also installed to give information about road conditions and speed limits which all helps smooth the flow of traffic, vary speed limits and manage traffic flows and incidents. 

We’ve also built five new emergency areas on this 10.5km stretch. These have emergency roadside telephones and CCTV cameras to improve emergency service response times. Combined with the stretches of hard shoulder that we kept, it means there’s somewhere to go in an emergency every 1.950 metres. 

This stretch also has a new concrete central reserve – which is much safer than the previous metal one, new noise barriers, better drainage and new low-noise surfacing. 

We also replaced the old Teapot Lane Footbridge at Aylesford with a new, wider bridge. 

People use the M20 for national, regional and local journeys and the motorway supports a lot of regeneration and growth in the area. The route also provides critical access to Dover, the Channel Tunnel, Heathrow, Gatwick and the wider south-east, south-west and the Midlands, via the M26 and M25. 

The changes we’ve made to the stretch between junctions 3 and 5 means therell be less congestion and shorter journey times. The road’s additional capacity will help support economic growth in the region.


Traffic information

Information about scheduled roadworks and events on our motorways and major roads.

Sign up for updates!

Keep up to date with what's happening on this scheme by signing up to our updates.