Before SH15 traffic is switched on to that new alignment, there will be new asphalt laid and the temporary guardrail and mobile safety barriers will be moved.
"The changes will mean trucks making a right hand turn on to SH1 will have a tighter turn than before. We ask truck drivers to go slowly and for northbound motorists to allow them as much space as possible to make the turn safely."
There will be a temporary speed limit of 30kmh at the Loop Rd intersection during the day on Tuesday as road crews work close to live traffic lanes. During night works on Tuesday, there will also be a temporary speed limit of 30km/h, with periods of stop/go traffic management on both SH15 and SH1 at Loop Rd.
"We ask motorists to slow down, keep to the temporary speed limits and watch out for our crews on the roadside. Safety is our priority and we want everyone to get home safely," Thackwray said.
This temporary intersection layout will remain in place for abut two weeks until the asphalting and work to connect SH1 and SH15 to the new roundabout is completed.
Traffic will then move on to the new single lane alignment through the roundabout.
Motorists have been using a temporary road past the Loop Rd intersection with SH1 while the new two-lane roundabout is built. The roundabout is part of a wider project to upgrade SH1 and the Portland Rd intersection further south to improve safety and access for road users.
The intersections are on a freight route for logging trucks heading to and from Northport at Marsden Point and 19,000 vehicles use this section of SH1 every day.