Almondsbury Interchange

The Almondsbury Interchange in South Gloucestershire, is one of the United Kingdom's largest motorway stack interchanges. The interchange is one of only three four-level stacks in the UK, spanning a range (including slip roads) of 1 km by 1 km. It is the interchange for the M5 at junction 15 and M4 at junction 20, and is situated at the northern fringes of Bristol close to the village of Almondsbury, the Aztec West industrial estate, and Bradley Stoke. When it opened in 1966, it was the most complex junction on the British motorway network, a free-flowing interchange on four levels. Since then traffic volumes have increased and at busy periods, the Interchange becomes more difficult to negotiate safely. A managed motorway project has been introduced in an effort to relieve congestion.The interchangeThe Almondsbury Interchange is immediately adjacent to junction 16 of the M5, which allows traffic on and off the motorway from the A38 road running between Bristol and Gloucester. In fact, it is so close that the slip roads from the A38 junction intertwine with those from the M5/M4 interchange. Unusually within the UK motorway system, this forces multiple lane changes for vehicles traversing some of the routes. The centres of the junctions are at Ordnance Survey Grid References ST 617837 (M5 J15/ Almondsbury Interchange) and ST 606833 (M5 J16/ A38), and are therefore 1.2 km apart.