The Peel Plaza development will cause big changes with the traffic flow in the vicinity of Union Street this week.
Starting on Thursday, Dorchester Street will be two way and no left turns will be allowed from Dorchester onto Union Street.
Wellington Row will be closed to thru traffic for about 2 months for construction.
The city is warning of congestion, especially during the morning rush hour, with between 5 to 6 thousand vehicles.
The city is also letting drivers know Lancaster Avenue is closed to traffic between Prince and Duke Streets and down to one lane at Dunn Avenue to allow for construction by Saint John Water.
Paving is expected to take place on Thursday and there's also paving in the area of Fundy Drive.
