Downer will soon add a second construction crew to the Caversham highway project to make the most of longer days and better weather.
About 20 full-time workers are developing the Caversham side of the four-lane highway, compacting a solid base for road layers to go on top.
They have had to move electricity and telephone lines aside, and embed a large stormwater pipe underneath to prepare for construction of the widened road.
Downer site engineer Pete Sleeman said it was an exacting process to ensure the base layers of the road were stable.
''The really important thing is getting that base right, because that's what everything is built on. It's crucial to have a good sub-grade, and we spend a lot of time testing it as we go in stages,'' he said.
Workers were starting to form the turns from State Highway 1 in and out of Burnett St, and level off a future footpath leading along the base of the steep bank on the left-hand side heading up to South Rd.
From September, another crew will be simultaneously continuing work on the Mornington side of the highway, below Lookout Point.
There, new streetlamps have been installed this week but have yet to be connected.
A footpath along the highway between Mornington Rd and Aberfeldy St will be completed, some reserve access roads tidied up, and the finishing touches put to a stormwater and discharge catchment at the intersection with Aberfeldy St.
''We'll put in some more lights and work towards getting that part ready for sealing,'' Mr Sleeman said.
Construction of the overbridge at the top of the hill will start early in the new year, New Zealand Transport Agency projects team manager Simon Underwood said.
''Geotechnically, the ground is quite challenging, and we've done some more geotechnical testing at the top. The bridge design has been reviewed in light of new information, so we expect construction to be January onwards.''
There were no major design changes, just tweaks to ensure the ground support and embankments were solid, he said.
The overbridge will be 7m above the road, allowing ample clearance for large vehicles.
It was hoped the newly formed lanes on the Caversham side of the highway will be ready for traffic by Christmas. Then workers will progressively move across the highway.
Mr Sleeman said next year's construction would be the most challenging, particularly while work was done between lanes of traffic up the hill, while at the same time the overbridge development at the top involved complex temporary intersections.
About 26,000 vehicles used the Caversham section of State Highway 1 each day.
''We are conscious of working around the traffic as best we can, to minimise disruption,'' Mr Sleeman said.
The entire multimillion-dollar project could be finished as early as December next year, although it could be February or March 2015 before workers move on, he said.
