A1(M) J1 South Mimms Interchange

Route

A1 and A1(M)

Junction number

1

Markerpost

23

Name

South Mimms Interchange

Terminus

Not a terminus

Other routes

M25, A1081

Authority

National Highways

Restricted turns

Full access

Services

Service area here

Service area name

South Mimms

Services operator

Welcome Break

Layout and signage

Stansted Airport (M11 Link)
Dartford Tunnel (M20 Link)
Heathrow Airport (M4 Link)
M25 Link
Barnet A1081
Services South Mimms
  M25
(M4)
   

M25
(M11)
(M20)

A1081
  Stansted Airport (M11 Link)
Dartford Tunnel (M20 Link)
Heathrow Airport (M4 Link)
M25 Link
Barnet A1081
Services South Mimms

Lane configuration

LanesLanesLanesLanesLanes

  • Lane 1 exits and does not return.
  • Lane 2 continues ahead.
  • Lane 3 continues ahead.

LanesLanesLanesLanesLanes

  • Lane 1 is gained from the entry sliproad.
  • Lane 2 continues, with option to exit.
  • Lane 3 continues ahead.

Other events

  • Signs Start of motorway regulations
  • Signs End of motorway regulations

In this section

What's new

Imperfectly Odd: Batheaston Bypass

It has viaducts, a tunnel and plenty of controversy, but the amazing Batheaston Bypass doesn’t really work. What went wrong?

South London's lost motorways

Completing the story of London's epic Ringways, we've just published the Southern Radials, five more motorways that never saw the light of day.

To the north east!

Two new additions to our collection of Opening Booklets take us to Darlington and Middlesbrough.

Share this page

Have you seen...

Low Emission Zone

A first step towards emissions-based road pricing, a pointless measure to enforce something that's happening anyway, or another leap forward in traffic planning from the people who created the Congestion Charge? It's hard to say.

About this page

Published22 April 2017

Last updated14 May 2022