Shoppers at Westfield Stratford City spent hours queuing to leave the centre this evening.
One shopper said she had been waiting for three hours in the car park before being able to move.
She said there were families with young children forced to wait in their vehicles while other motorists decided to leave their cars parked overnight.
She criticised the car park staff for failing to tell motorists anything.
A woman working at the car park office said there was a problem with traffic lights on the main road.
A spokesman for Scotland Yard said they had received reports of traffic disruption involving 70-80 cars.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here