The M10 may have been a short little motorway, but its inception was to make it an extremely important addition to the motorway network. It was also one of the first motorways to be built, and along with the M45, is the first complete motorway to open - in that no extensions were proposed, unlike with the M1 and M6.
The motorway was only three miles long, but its short length did not take away from it the importance it held. Its terminal roundabout also has a claim to fame, in that it forms the basis of an example sign shown in the Highway Code.
This is a story of a motorway legend: the story of why the motorway was conceived, and what led to the decision to take its status away.
Why the motorway was built
The M1 motorway was originally planned to form the main part of the London to Birmingham Motorway and would have run from the A41 on the edge of Watford up to the A5 at Crick. All was well with the plan right up to the 11th hour when it was realised that there was a major problem with the proposed motorway.
The flaw was not with the design of the motorway itself, but with the roads at either end. At the time, both the A5 and A41 were standard single carriageway roads, and it was recognised that these roads would not be able to cope with the expected volumes of traffic that were likely to use the motorway, especially as the M1 would provide a fast route between the Midlands and the South East.
A decision was therefore made to revise the scheme, with the addition of two spurs, one at either end of the M1. At the northern end was the M45, whilst the M10 would be the spur at the southern end. The idea behind the spurs were to split the traffic between the mainline and the spur, so that traffic was distributed over a greater area, reducing the likelihood of gridlock at either end of the M1.
A three-mile long route around the southern end of St Albans was chosen, which would allow traffic to head onto the North Orbital Road (the A414 and A405), the predecessor to the M25. The motorway could also be used to remove through traffic from St Albans centre, as it would combine with the M1 to form a bypass for the town.
The motorway opens
The M10 was designed by the transport department of Hertfordshire County Council on behalf of the Ministry of Transport and was constructed by Tarmac Ltd.
Due to its short length, the M10 formed part of the larger contract for southern half of the M1. The motorway itself opened alongside the M1 and M45 on 2 November 1959.
It lived a relatively quiet life, with no changes made to it during its 50 years in existence. It also served its purpose well, despite being eventually superseded by the M25 in 1986. It was often thought that the M10 may have been extended to meet the M25 at Junction 22, but no evidence of that link being planned has come to fruition - instead the A414 and A1081 provide that link instead.
Given the M25 would only be one junction further south from the M25, and with free flow links being built between the two M1 and the M25, building such an extension would have simply been an unnecessary expenditure. The only benefit, perhaps, would be to shave a couple of minutes off journey times.
Demise and declassification
In the end, the M10 would simply become a left-over relic from the earliest days of the motorway network, and its purpose had simply been eroded due to the M25. Yet it could not simply be downgraded as there was no escape route for prohibited traffic to take. So the Highways Agency had to leave it be - that is until they realised the M1 was struggling under the weight of the traffic using it.
Because of the need to increase capacity, the Highways Agency envisaged they could remodel the junction layout to link the M10 junction (J7) with the next one up (J8). It would make sense as it would provide a non-motorway link between the two sections of A414, and could remove traffic from St Albans that would otherwise have been forced to travel through the town.
To do this, a pair of distributor roads were built to run parallel to the motorway. These links would be classified as part of the A414, so would not form part of the motorway as traffic would not need to touch the M1 mainline to access them. For the first time, this created an escape route at the eastern end of the M10, meaning it no longer had to be a motorway.
As a result, the Highways Agency applied to have the M10's motorway status revoked. This was passed in 2004, but could only be applied once the distributor roads were constructed and the widening works completed. The schedule was for the M10 status to be removed once and for all in late 2008, but due to delays in the work, the status was not revoked until 2009.
The M10 now merely forms part of the A414, although some restrictions are still in place, and the hard shoulders remain!