Traffic in the car park at Princes Mead, Farnborough, was brought to a standstill for more than an hour on Sunday, due to building works closing one of its exits.
Witnesses said the traffic caused arguments among customers and children were crying. The jam was only cleared after an Asda employee opened the emergency access.
An Asda customer, who wished to remain anonymous, said: “It just all kicked off outside Asda.
“I have never seen anything quite like it in 20 years of living in Farnborough.
“The car park came to a whole standstill. It got to the point where everyone was moaning and people were getting out of their cars and standing on the rims and trying to look at what was going on.”
They added: “People were arguing and children were crying.
“One woman said she had been there more than an hour but I couldn’t see what was going on.
“There didn’t appear to be an accident or car broken down, but with all of the extra traffic headed out of the one exit from Asda, and with traffic from B&Q and the industrial estate all going into the same road, it all just built up.”
A statement from Asda said the issue was caused because the secondary exit to the shared car park had been closed as part of ongoing development work at the shopping centre.
A spokesman for the company added: “With it being a sunny day, the car park was busy and the sheer volume of traffic resulted in a jam. As soon as colleagues were aware of it, a team went out into the car park and tried their best to help the situation and the backlog of cars was cleared by around 2pm.
“We completely appreciate this situation was really inconvenient for customers and we tried to solve it as quickly as we could.”
A spokesman from Princes Mead said they could not comment as the car park was owned by Asda.