The Gravelly Hill Interchange, popularly known as Spaghetti Junction, is a road junction in Birmingham, England. It is junction 6 of the M6 motorway where it meets the A38(M) Aston Expressway in the Gravelly Hill area of Birmingham. The interchange was opened on 24 May 1972. The structure was designed by engineer Sir Evan Owen Williams.
The junction is designed to last 120 years.
Courtesy Historic England
It covers 30 acres (12 ha), serves 18 routes and includes 4 km (2.5 mi) of slip roads, but only 1 km (0.6 mi) of the M6 itself. Across five different levels, it has 559 concrete columns, reaching up to 24.4 m (80 ft). The engineers had to elevate 21.7 km (13.5 mi) of motorway to accommodate two railway lines, three canals and two rivers.
During the first year of opening, the average flow of vehicles was 40,000 per day. Today, the average daily flow is over 200,000.
Work was mostly complete by May 1970, and attracted attention of local residents. By the following September, several motorists were found to have been driving illegally along it, and children had found it a useful shortcut to school.
By 2009, it was estimated that 1¼ billion vehicles had travelled through the junction, and although structural defects had been found, the overall structure was stable enough to continue carrying traffic.
In an interesting meeting of old and new methods of transport, the pillars carrying Spaghetti Junction over the canal network had to be carefully placed to allow a horse-drawn narrow boat to pass underneath without fouling its tow rope.
In 2022, for the 50th anniversary of the opening of Spaghetti Junction, Heinz released a limited edition of their tinned spaghetti featuring the interchange on the tin.
The Highways Agency spends approximately £7 million a year to maintain Spaghetti Junction in a safe and serviceable condition. Concrete repairs are carried out in small sections, so the overall strength of the supporting beams is never compromised. During concrete repairs, small sections of old concrete are cut out using water. Using water rather than physical tools removes the risk of damage to other sections of viaduct through vibration.
If you wanted to drive along every road at the Junction itself, adhering to the Highway Code, you would have to travel approximately 73 miles.
Spaghetti Junction appears in the Guinness Book of World Records, as “the most complex interchange on the British road system”.
