Unlucky 13 - the M1 junction's weirdness explained

As a frequent traveller to Bedford via Milton Keynes and the A421, I have often wondered why this road suddenly and inconveniently veers south-east and travels alongside the M1 motorway for a couple of miles before meeting it at junction 13, and then goes north again on the other side, adding several unnecessary miles to the journey. Having discovered that junction 13 itself in its original form featured in road enthusiasts' website CBRD's list of bad junctions, piecing together the various reader comments solved the mystery of the bigger picture and why the entire road layout in that area is a bit strange, so here is the explanation.

Why does the A421 go down to the motorway junction and back up the other side? Read on to find out...

The simplest explanation would be to suggest that junction 13 is in the wrong place and should be a bit further north, but actually the junction was in existence almost a decade before development work began on the New City of Milton Keynes, having been built as part of the original motorway construction in 1959. In those days it didn't serve anywhere particularly important, just a handful of villages and a brickworks where the Amazon distribution centre is now sited, and its builders could not have foreseen the growth of a whole new urban area in its vicinity.

So if the junction was already there, why wasn't Milton Keynes designed with a direct connection to it?

Actually it was. According to the original plans, the H8 Standing Way, also known as the A421, was never intended to connect with the motorway at all. Instead, this role was to have been performed by the H10 Bletcham Way, two blocks further south, which would also have provided a more direct link between the M1 and A5. However, the proposed route cut right through Wavendon, one of the old villages now on the fringes of the new city, and the residents voiced strong objections to the disruption it would cause, which were upheld by the planning authorities. As a result, the H10 terminated at Wavendon and the southern extension of the H8 was bodged in instead to meet junction 13, hence its deviation from the usual east-west alignment of H-roads as a rare exception to the city's otherwise carefully-designed road network.

Even today the intention is clear when looking at a map. Find the end of the H10 in Wavendon, where the A4146 turns left onto the V11 Tongwell Street, and follow its line east, roughly parallel to the railway. Guess where it ends up...

The red line shows how the H10 should have connected Wavendon to J13. It seems so obvious.

So with the H10 providing the motorway link, the H8/A421 would have been free to avoid junction 13 entirely. Where it bends to the right to run parallel with the motorway, it should probably have instead gone straight over on a bridge and joined up with the existing alignment on the other side, providing a more direct uninterrupted route to Bedford and eliminating the 'down and up' section around J13.

What would the unbuilt road have been numbered?

A good question as it seems likely that the Bedford road (H8) would have retained the A421 number, so the H10 to junction 13 would need another number. The existing stretch from the A5 to Wavendon is part of a small out-of-zone section of the A4146 that is not directly connected to the bulk of this road as the A5 itself is multiplexed for one junction. Assuming the A-road status stopped at the A5 junction as it does now and the H10 to the west would purely be a local road, this stretch would be entirely to the east of the A5 and thus fully within zone 5, and its role as a motorway link suggests a three rather than four-digit number would have been appropriate. The A507 from mid-Bedfordshire now terminates at junction 13 so the unbuilt section of H10 could possibly have continued this number; this is pure speculation however as the A507 was only joined to the junction in 2008 but this may have been planned much earlier.

Why is this section of A421 single-carriageway?

As with so many things these days, this is apparently down to bureaucracy and lack of joined-up thinking between different parties. The area is on the borders of two authorities, and the Milton Keynes Development Corporation was happy to make its part of the A421 dual-carriageway, but could only go as far as the county boundary. The section parallel to the motorway is in Bedfordshire, whose County Council was unwilling to do the same, the justification being that a good-quality link here would cause visitors bound for Bedford to divert to Milton Keynes instead and spend their money in another authority's jurisdiction, depriving Bedfordshire of valuable income.

Even after the dual-carriageway A421 Bedford bypass and related remodelling of junction 13 was completed in recent years, this short section remains unchanged and is a considerable bottleneck as it is now the only single-carriageway part on the near-30 miles of A421 between Newton Longville and the A1 junction at Roxton. Substantial roadworks are currently being carried out on the northernmost part around the Magna Park industrial development, adding further delays, but it is unclear what they intend to achieve and the bulk of this section has been left untouched so the works don't appear to be related to dualling the road.   

A little oddity...

Until recently a very odd little feature could be spotted on the A421 alongside the motorway by observant motorists. Around a mile north of junction 13 on the northbound side stood a lonely little sign simply pointing straight ahead to the M1. There are no turnings on this road before reaching Milton Keynes, and the next opportunity to join the motorway is not until junction 14 to the north of the city, so this sign's sole purpose appears to have been to help those unfortunate drivers heading for the motorway who managed to miss the badly-arranged entrance slips at junction 13 and were unable to turn around. Surely that was an admission of J13's inadequacy as a major interchange, although it appears to have been removed now that the layout of the junction has been improved.  

So there you have it

Like so much of the British road network, this area seems to be a mess because common sense was abandoned in the face of NIMBY opposition and bureaucracy, forcing an inadequate bodged up solution to be put into place under the control of different authorities who don't always see eye to eye. In the long run, the problems of congestion and the regular need for costly and inconvenient improvements caused by such bodgery and last-minute alterations must end up outweighing the reasons for the objections to the original plans. At least the strangeness of the A421 between Milton Keynes and junction 13 can be explained as a compromise and it wasn't meant to be that way, but we are stuck with it now.