The lane closure in Church Street due to an unsafe building looks set to continue throughout this week.
Preston City Council took emergency action on Friday 14 June.
Conditions of 132 Church Street have deteriorated causing the city council to inspect it.
Temporary traffic signals are in operation from the junction with Manchester Road up to the Minster.
A spokeswoman for the city council told Blog Preston: “We are working with the owner of the building. He has appointed a structural engineer to advise on the next steps.
“As safety is a priority, the traffic management control will remain in place until the building is secure which could take the rest of the week.”
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