Motorists endured queues of traffic due to repairs to traffic lights.
Cars and lorries were snarled up in traffic on Thursday morning with one lane closed.
Reports on social media claimed one lane on the bridge was coned off, leaving only one lane for traffic to filter into.
One motorist reported it took two hours to travel to Lancaster from Morecambe.
Other motorists took 40 minutes to travel from the Heysham bypass roundabout to Asda.
Police said there hadn’t been any accidents which might have explained the hold-ups and a spokesman for the Heysham M6 link said there were no link roadworks underway which could have caused the extensive delays.
The traffic had cleared by early afternoon on Thursday.
Peter Bell, network control manager for Lancashire County Council, said: “We needed to carry out repairs to the traffic lights, which meant we had to close a lane.
“The work started and finished yesterday.
“We appreciate that there’s never a good time to close part of a busy road such as this.
“The work was done after the morning rush hour to minimise the disruption during the busiest part of the day. We apologise for any inconvenience caused by this work.”