As traffic once again came to a standstill on the major highway between Perth and Margaret River today, Western Australia's transport minister promised the end was in sight for traffic woes in the region.

The state government is building a $1.35 billion dollar bypass road around Bunbury while simultaneously widening the road between Capel and Busselton after years of fatal crashes and near-misses.

Roadworks for the two major road projects on the notoriously busy Bussell Highway have frustrated locals and tourists travelling between the city and WA's premier wine region for months.

In the early hours of this morning a truck rollover near the roadworks closed the northbound lane of Bussell Highway, resulting in traffic delays going into mid-morning.

The truck was towed away about 10am.

Projects to finish by end of 2024

WA's Transport Minister Rita Saffioti said there was an end to the havoc in sight.

"They are big projects, and I know it has created inconvenience for people travelling and living in the South West. We apologise for the inconvenience," she said.

"But these projects will completely change the driving experience heading down to Busselton and Margaret River.

Ms Saffioti said the projects were incorporated to make sure the Bussell Highway duplication was done at the same time as the Bunbury Outer Ring Road.

"The aim is to not just push the bottleneck further down the South West," she said.

The Bunbury Outer Ring Road is the largest infrastructure project to ever happen in WA's South West and will be a 27-kilometre four-lane road linking the major highway from Perth to the road to Margaret River.

It will mean travellers going south will skip 13 sets of traffic lights, making the trip 11-18 minutes quicker.

The ring road has not come without criticism with people trying to stop the road for happening altogether.

It has had multiple cost-blowouts and been criticised by environmentalists concerned about clearing the habitat of the critically endangered western ringtail possum.

But Ms Saffioti said the new infrastructure would ultimately bring positives for the growing tourism region.

"It was not an easy decision, but if it wasn't made it would only make the issue of congestion worse for future generations," she said.

"Without reduced congestion and improved connectivity the whole South West will suffer because people will just not make the effort because it'll take too long to get down there.