Osmond said the aim of the project was to ensure the entire town's bridges, especially on country roads, could handle heavy trucks and high-productivity motor vehicles.
"Once the project is completed, Wairoa will have a safe, future-proofed road network that will allow businesses to deliver their goods to markets without the present restrictions on load size."
"This will help these businesses thrive, while providing economic growth and jobs to the people of Wairoa," Osmond added.
Wairoa Mayor Craig Little said the work would not have been possible without the PDU funding.
"This is a great example of local and central government working together for the benefit of communities like Wairoa," Little said.
The large volume of timber expected to be harvested in Wairoa's exotic forests over the coming decade is one factor being used to help identify bridges which need strengthening.
Osmond said detailed work had been done looking at the amount of timber that will be transported to market in the coming years.
"The result of that work has been used to identify high-priority routes which need upgrading to full HPMV capability," he said.
"One of the key forestry routes over the next 10 years is to the Mahia Peninsula."
This route also serves as an access route to New Zealand's rocket launch facility, Rocket Lab.
The latest bridge earmarked for upgrading is Doughboy Bridge on Ruakituri Rd.
Work begins on Monday, January 18 and is expected to take three weeks.
Ruakituri Rd will be closed for the meantime and motorists will have to take a detour.