Commuters experienced huge delays today after structural problems were found in pillars supporting a section of Spaghetti Junction leading into Birmingham.

And delays will continue for at least a week as a vital sliproad is kept closed while repairs take place, the Highways Agency said.

Three sliproads at Spaghetti Junction leading onto the A38 Aston Expressway were closed on Thursday night after the structural problems were found – the link from Tyburn Road, the A5127 from Erdington, and the link from the northbound M6. They were temporarily closed at 10pm on Thursday night for works after problems in the pillars supporting the M6 link were found, and were due to reopen at 6am today.

But work continued on the Tyburn Road link throughout the day, causing chaos for motorists coming into the city on one of the major commuter routes.

One disgruntled worker said: "The A38 was a car park and there must have been hundreds of people late for work because it was just not moving. It took me 45 minutes to cover just a few miles and that was only because I gave up, turned round and went another way."

And there were reports of more delays in the evening rush hour, despite the roadworks being in place on incoming sliproads.

A spokeswoman for the Highways Agency said: "The link from Tyburn Road to A38 Aston Expressway will be closed until the week commencing December 3.

"The A 5127 from Erdington to A38 Aston Expressway will be restricted to a 30mph speed limit but will be closed on Saturday night and Sunday.

"The link from M6 Northbound onto Aston Expressway will be closed on the night of Saturday, November 24.

"We anticipate that two further overnight closures of this slip road will be required at dates determined by progress of work on site."

The spokeswoman also said Spaghetti Junction required constant and prompt maintenance, adding: "Spaghetti Junction is like our Forth Bridge, we are investigating it, checking it and maintaining it constantly.

"She's 35 years old now and carrying twice the amount of traffic she was built for. We're aware that this is coming during one of the busiest weekends of the year before Christmas for retailers. We apologise for any inconvenience to drivers, and advise them to allow more time for their journeys."

During the continued closure, drivers will be diverted onto Salford Circus roundabout and Lichfield Road to Dartmouth Circus to access the A38 city-bound.