Changes to the location of the transitions, the finish line and the route for the bike leg are the most notable differences to the course for the 2011 Ironman triathlon announced yesterday.

The Ironman Australia triathlon finish line will move from Westport Park to Town Green, and the Food-for-Less car park will be where athletes change, or transition, from the swim to the bike leg this year.

World Triathlon Corporations (WTC) brand manager Trent Taylor said spectators and local business would benefit from the new finish line at the May 1 event.

"The accommodation is closer you've got your restaurants, bars and clubs, which provides people with something to do all day," he said.

"Last year, a lot of people came over here, anyway."

The Town Green will be transformed using a 80m x 20m function marquee, a finish line and a stage ahead of the race in May.

"No location is ever 100 per cent ideal, but we are fairly flexible with our infrastructure," Mr Taylor said.

The bike transition location also has been moved to the Short St car park 150; with bike racks, a bike finish chute and timing mats replacing cars on the day.

Most notably, the bike leg will take a new route this year.

Mr Taylor said it was a requirement of the WTC that the bike leg be changed to two 90km laps instead of three shorter laps to bring Port Macquarie's event in line with other Ironman triathlons held around the world.

This was the main driver behind Port Macquarie-Hastings Council's decision to incorporate the streets of Bonny Hills and Lake Cathie into the bike leg, which also will take in the southern townships of Laurieton and Dunbogan.

Local Organising Committee chairman Greg Laws said more roads needed to be closed for this year's event.

But businesses in Bonny Hills and Lake Cathie would see a positive effect.

"There were many options that we looked at, and we considered how it would effect residents," he said.

"It was all about keeping the event here."

He said the organising committee was prepared for negative reaction when affected locals were notified this week.

"We haven't had to gauge community response yet, but when it's rolled out there will be a hotline set up," Mr Laws said.

During the event, road access will be limited to emergency services. But a minibus service is expected to operate for residents who need to get to work.