The second phase of a major road improvement scheme is due to get under way on Lincoln's High Street.
The six-month project to revamp footpaths, create new parking bays and a bus lane is being carried out in three phases.
The first - between the Portland Street and Dixon Street junctions - has now been completed.
From Monday, Dixon Street will be closed between the High Street and Boultham Park Road for about six weeks.
In addition, some bus services in the area are using alternative routes.
Motorists have been warned to expect disruption during the work, which is due to be completed by the end of October.
Peter Saxby, senior engineer at Lincolnshire County Council, said: "As a result of the work taking place, congestion will reduce and traffic flow will improve in the area.
"People can use better-quality pavements and public transport will be more reliable, so do please bear with us."