Motorists travelling through Anniesland Cross, in west Glasgow say the council has changed the phasing of the traffic lights.
The move is resulting in fewer cars getting through the lights, causing frustrated drivers and major tailbacks.
They are calling on the council's roads department to fix the issue if it is a glitch - or explain why the phasing was changed.
The junction is one of Glasgow's busiest, linking arterial routes, including Crow Road, Great Western Road and Anniesland Road.
Print firm worker David Hunter, who travels from his home in Milngavie to his East Kilbride office daily, said he experienced similar problems in December.
The 43-year-old said: "The council changed the phasing of the lights just before Christmas.
"I had never had a problem before but it took me about an hour and a three quarters to get home when it changed. My journey at peak time usually takes an hour.
"There was queuing traffic all the way from the Clydeside Expressway to Anniesland Cross.
"That lasted a few days so I stopped travelling that way."
Mr Hunter said he realised the phasing had returned to normal and started using the route again.
However, last week drivers were hit again.
Mr Hunter said: "They used to be well-timed so you would get through two sets of lights at a time.
"It has become a total gridlock again. It's just farcical. The traffic flow was much better before."
James Young, who works at a design agency in Glasgow City Centre, drives from his home near Drymen using the route through Anniesland Cross.
The 42-year-old said his journey at peak times usually takes 35 minutes - but with the traffic light changes, the journey takes 75 minutes.
He said: "Anyone who drives that way will understand how frustrating it is. Only half-a-dozen cars get through at a time now and before there were no problems.
"I've phoned the council and they said I couldn't speak to anyone so I can't even find out why they would change the way the lights operate."
A Glasgow City Council spokesman said upgrades to the traffic light system at Anniesland Cross were carried out this month.
He added: "This was done to bring the lights in line with standard sufficient crossing times for pedestrians. We have carried out further adjustments on the back of site visits and these have improved traffic flow.
"The lights will continue to be monitored to balance the requirements of all road users."