Drivers were stuck in gridlock across Northampton on Friday with shoppers being reportedly stuck in town centre car parks for up to two hours.
Motorists resorted to social media to try to find out the cause - but there were no reported accidents, just sheer weight of traffic as people left work and got in some last-minute shopping.
At 5pm on Friday night, traffic maps showed severe delays on virtually every road in around the town centre.
Dozens of people tweeted the Chronicle & Echo's Twitter account.
Guy Bailey @GPBailey said: "Be warned if you’re off to the Gardens. Northampton is gridlocked!!"
Sue Hope @SueHope64 added: "Two hours in a car park, why?"
Dee Bee @deebee123 said: "What is going on???? this is a joke. Nothing moving......"
Tom Townsend @_tomtownsend said: "People haven't moved in the Mayorhold car park for 45 minutes. I let a car out, parked, went shopping she's still here!"
Not everyone was sympathetic though.
Jessica Lynch @jessielouly said: "What Northampton needs is for people to think twice about DRIVING to town on the busiest shopping day of the year! And if you have to, do it earlier and not during rush hour when everyone is trying to get home from work!"