M1 junction 12 Toddington traffic light work

The work will be completed in phases, starting with the northbound. 

We’ll need a series of overnight closures starting Tuesday 1 September until Saturday 23 January 2027.

The work will take place between 9pm and 5am, Mondays to Fridays, weather permitting.

Temporary traffic lights will be in place at both junctions, Harlington Road (B5120) and the B530, slip road closures, lane closures and a temporary 30mph speed limit. 

Closures and diversions

Tuesday 1 September and Wednesday 4 November 2026  – M1 northbound exit slip road at junction 12.

Fully closed weeknights  (9pm to 5am) 

Diversion

• continue northbound on the M1 to junction 13
• at junction 13, take the A421 exit towards Bedford/Milton Keynes south
• at the roundabout, take the fourth exit onto Bedford Road/A507
• at the roundabout, take the third exit to return southbound via the M1
• continue southbound on the M1 back to junction 12
• leave the M1 via junction 12 southbound exit slip to continue your journey

As well as the slip road closure, switching lane closures will be in place on Harlington Road (B5120) and the B530.

Wednesday 4 November 2026 to Saturday 23 January 2027 – southbound junction 

Fully closed weeknights  (9pm to 5am)   

M1 southbound entry slip road or southbound exit slip at junction 12, depending on the phase of works closure.

M1 Southbound Junction 12 exit slip road closure:

• 4 November 2026
• 6 November to 13 November 2026
• 30 November to 3 December 2026
• 10 December to 14 December 2026
• 8 January to 13 January 2027
• 22 January 2027

M1 Southbound Junction 12 entry slip road closure:

• 5 November 2026
• 16 November to 27 November 2026
• 4 December to 9 December 2026
• 15 December to 18 December 2026
• 5 January to 7 January 2027
• 14 January to 18 January 2027
• 21 January 2027

Southbound exit slip road diversion route:

• continue southbound on the M1 to junction 11A, whereby it will leave the M1
• at Chalton roundabout, take the third exit
• rejoin the M1 northbound towards junction 12
• leave the M1 at junction 12 via the northbound exit slip to continue your journey

Southbound entry slip road diversion route:

• continue along Harlington Road to the roundabout
• at the roundabout, take the fourth exit and return via Harlington Road to the northbound side of the junction
• join the M1 via the northbound entry slip and continue northbound to junction 13
• at junction 13, take the A421 exit towards Bedford/Milton Keynes south
• at the roundabout, take the fourth exit onto Bedford Road/A507
  at the roundabout, take the third exit to return southbound via the M1
• continue southbound on the M1 back to junction 12 to continue your journey

Alternative diversion route

On the following dates, alternative diversion routes will be in place due to other planned closures on the M1: 

Friday 25 September 2026 – 9pm and 5am

For traffic affected by the diversion route:

• continue on the A5120 Harlington Road towards Westoning
• continue on Flitwick Road through Flitwick
• join Ampthill Road (A5120) northbound
• continue onto the A507
• rejoin the M1 at junction 13 and continue your journey

Thursday 19 November 2026 & Thursday 21 January 2027 – 9pm and 5am

For traffic affected by the diversion route:

• leave the M1 at junction 13 and travel eastbound on the A507
• continue on the A507 towards Flitwick
• join Ampthill Road (A5120) southbound
• continue through Flitwick onto Flitwick Road
• turn right onto the A5120
• continue towards junction 12 and Harlington Road to continue your journey

Emergency vehicles and residents directly affected by our work will be escorted through the roadworks. 

Please remember that closures can change at short notice. You can check the latest information on our daily closures page. Our travel alerts give details of live incidents on our network.

Background

The M1 is one of the busiest motorways in the country.

Around 125,000 drivers rely on it every day for work and leisure, with a higher than average number of heavy goods and other vehicles between London and the North.

So it's important that we keep it well maintained. 

This work will help ensure that the traffic lights at the junction work smoothly.