Site investigation works on the Joy Baluch AM Bridge Duplication Project are scheduled to begin next month and continue until early August.
The Department of Planning Transport and Infrastructure has advised of shallow excavations underneath the bridge to further investigate existing ground conditions.
Activity, adjacent to Tassie Street, is expected to have some impact on pedestrian movements in the area.
"Signage will be in place to alert pedestrians to any changes to conditions. Pedestrians are advised to take care when in the vicinity," a spokesperson for the project said.
"During the works, you may notice the increased presence of machinery as well as ground personnel.
"Some minor noise disturbance can be expected at times as you may hear sounds from the equipment used and vehicle movements."
The state government revealed the first artist impressions of the new bridge earlier this year, setting a completion date of 2022.
The project will see a duplication of the existing two lane bridge, as well as widening the approach roads to allow for two lanes in both directions between Mackay Street (south of the bridge) and Burgoyne Street (north of the bridge).
Pedestrian causeways will be installed on both sides of the bridge, with the new structure having no impact on the defunct Great Western Bridge.
Negotiations involving land acquisition south of the bridge near Mackay Street are underway, although it is unclear how many residential addresses will be impacted.
The intended works will begin on Monday, July 15 and continue till early August - weather permitting.
All works will be performed during the day.