Motorists are being urged to be patient while road users get used to the new road layout in Penwortham.
John Horrocks Way opened on Monday, causing confusion and delays among drivers.
Read more: New bypass menaces woman who only wanted a nice hotpot
Many took to social media to express their frustration at the congestion in Penwortham during rush hour.
Lancashir County Council has now issued a statement, saying: “Thank you to everyone who took the time to contact us about your experiences following the opening of John Horrocks Way and the related highway changes on Monday morning.
“Following the opening of the new bypass, we started the final construction work for this scheme with the temporary closure on Liverpool Road near Howick Moor Lane.
“Please bear with us for a few weeks, until this has been done.”
LCC said the new bypass is intended to reduce congestion through the centre of Penwortham, which has been gridlocked at peak times for a number of years.
A spokesman said “We recognise that it has been disruptive and are working to get Liverpool Road open again as soon as possible. Once we have completed this work, the situation will improve.
“As with any major road scheme, there can be issues that only crop up once people start using it, and we’ve already been looking at how we can improve the situation.
“The new bypass has only been in use since Monday, and there is still significant work taking place which will continue to affect journeys through the area. “
Temporary measures have been put in place to alleviate problems at the traffic lights at Golden Way, on the approach to the flyover. A permanent solution will be implemented in due course.
However the slip road from Liverpool Road to Guild Way will remain closed.
Read more: Major changes planed for Liverpool Road once bypass is opened
The LCC spokesman said: “We are aware that there have been some issues on the road network over the past few days, with queuing at times especially on some local roads.
“We’ll continue to monitor the traffic levels as people become more familiar with the new layouts and routes.
“There is a signed diversion in place along the A582 Golden Way, to reduce traffic using smaller residential roads.
We remind people that they can access Golden Way by turning right at the “bottom of Penwortham Hill. This avoids the need for some drivers to choose to travel along Cop Lane to access the road.
“There are no plans to reopen the slip road onto Guild Way, as this would affect the new flow of traffic along Golden Way towards Preston.
“It is also part of the wider measures to encourage people to use John Horrocks Way in the future, rather than travelling unnecessarily through Penwortham.
“There are many signs up around Penwortham to let people know about the road closure at Liverpool Road, including on key approach roads, and we publicised these changes through the media, social media and newsletters ahead of the work taking place.
“We ask people to please be aware that the road layout has changed significantly in this area, and keep an eye out for signs showing the diversion or road closures which could affect their usual route.
“Please allow more time for journeys while this final work is taking place on Liverpool Road. We’ll re-open it as soon as we can.”
Have you used the new bypass yet? Or been affected by congestion in Penwortham? Let us know in the comments section.