The $497.3 million Mackay Ring Rd project is on track for completion in late 2020 after passing a number of milestones in recent months.
A Transport and Main Roads spokesman said procurement activities were nearing completion, with subcontracts previously awarded for all major components.
The Mackay Ring Road (Stage 1) involves the construction of 13 bridges, including four water crossings and nine overpass structures.
The department says the last of 462 piles are in place, including those for the new Pioneer River bridge (see footage below).
This month saw overall works advance to the point where 98 per cent of pre-cast pipes and box culverts for the project have been installed (about. 4km).
Early next year should see earthworks complete and Peak Downs Highway traffic switched to the completed alignment.