Route
Junction number
4B
Markerpost
27.5
Name
Thorney Interchange
Type
Terminus
Not a terminus
Other routes
M25
Authority
Restricted turns
Full access
Services
No services
M4 J4B Thorney Interchange
Layout and signage
Lane configuration
- Lane 1 exits and returns after the junction.
- Lane 2 exits and returns after the junction.
- Lane 3 continues ahead.
- Lane 4 continues ahead.
- Lane 5 continues ahead.
- Lane 1 exits and does not return.
- Lane 2 exits and returns after the junction.
- Lane 3 continues ahead.
- Lane 4 continues ahead.
- Lane 5 continues ahead.
Other events
Variable Speed Limits apply
- Variable Speed Limits apply
What's new
A century of motorways
It's 100 years since the opening of the world's first motorway, the Autostrada from Milan to the Lakes.
Schrödinger’s speed limit
In 2022, Manchester City Council say they reduced the speed limit on the Mancunian Way to 30mph. But it’s not clear if they did. It’s not even clear if they can.
Sorry, wrong number
Road numbering is a system with clear rules. What happens when the people responsible for numbering roads don't follow them?
Have you seen...
Junction Three
The M621 has one junction where everything leaves the motorway and heads for the city, and a very bizarre junction it is too.
About this page
Published
Last updated
Published
Last updated
