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Route of the M10

The M10 is the original southbound distributor for the M1, now downgraded to A-road status. The reason the seemingly unimportant M10 existed goes right back to when this bit of the M1 opened in 1959. There were no other connections (there were, for that matter, barely any other motorways) so all the M1's traffic had to return to the old road network.

There was no way that any road in the vicinity could cope with six lanes of high speed traffic being dumped onto it. So at each end, a spur was built heading off towards a popular destination, with the hope that lots of traffic could be removed from the road before it slammed into the terminal roundabout. In the north, the M45 carried traffic onto the A45 to Birmingham; in the south the M10 dropped traffic at the A414 and A405, the predecessors to the M25.

In later years the M10 was a bit redundant, forming a third of a St Albans bypass. Ideally it could have continued a bit further to connect to the M25, alleviating congestion at the M1/M25 interchange, but this extension was never forthcoming.

When the M1 was upgraded to four lanes between the M25 and Luton, the M10 was killed off. Collector-distributor roads were built alongside the M1, and the A414 was routed on what was the M10, up the parallel carriageways alongside the M1 and off to join the next section of A414 at junction 8. The M10 shared the honour of being the second British motorway with the M1 and M45, but was reduced to A-road status less than a year before its fiftieth birthday.


Start Potters Crouch (M1)
Finish Park Street (A414)
Passes St Albans (nearly)
Length 3 miles
Connects to M1


Views of the M10 from on and off the road. If you have a photo to contribute, contact me.


The M10, seen in its final days heading towards St Albans. The yellow sign indicates the end of the free recovery service through the M1 roadworks.
Photo by Simon Harding


The end of the line: the direction sign for Park Street Roundabout, which is just around the corner.
Photo by Simon Harding


Approaching from the A414, the famous sign for Park Street Roundabout shown here was used for years in the Highway Code as the example for roundabout signs.
Photo by Robert Sprigge


The entrance to the M10 from Park Street, with important-looking blue signs. This is all now green and the signs say A414 instead.
Photo by Robert Sprigge


The 'start of restrictions' sign - now gone.
Photo by Robert Sprigge

Construction Timeline

When the various parts of the M10 were built, listed in chronological order.

Open Jct Section
Nov1959 Entire motorway

Exit List

All the junctions and destinations along the route.

This route was downgraded in 2009 and is no longer a motorway. The exit list here shows the road as it was before downgrading, and is no longer accurate.

Junction   Westbound               Eastbound
(M1 J7)
36.5 km
M1 Link
Beechtrees Inerchange (Fork)
M1 N/A More information about this junction
LanesLanesLanesLanesLanesLanesLanes LanesLanesLanesLanes
3 miles, 2 lanes Up   Down 3 miles, 2 lanes
32.4 km N/A A405


Park Street Roundabout (Roundabout)

St Albans
Chiswell Green
More information about this junction
LanesLanesLanesLanesSigns LanesLanesLanesLanesSigns