A 3D video of the stages of the project can be viewed below.
"The project will separate State Highway and local traffic, easing congestion and improving safety as Tauranga continues to grow now and into the future," Mr Bridges said.
"The underpass will also make it safer and easier to walk and bike around this area, with new paths and a cycling and walking bridge over SH29A to be built," he said
Mr Bridges said one of the important drivers of economic development was unlocking key congestion points to get people and freight moving more effectively around the city.
The Maungatapu underpass project is one-tenth the size of the Tauranga Eastern Link project, but it was a vital part of the NZ Transport Agency's long-term plan to create a ring road around the city.
It meant more than three quarters of a billion dollars of roading investment in the area. Mr Bridges said: "The ring road will be made up by the completion of this underpass - as well as the rest of the Hairini Link project - along with the $455 million Tauranga Eastern Link, the $68 million Route K and the upcoming $102 million Baypark to Bayfair project."
Also at the sod-turning yesterdaywere Bay of Plenty MP Todd Muller and Rotorua MP Todd McClay, TaurangaCity Mayor Stuart Crosby, other councillors, regional and local members of the NZ Transport Agency, and representatives from Fulton Hogan who will construct the underpass.
Representatives from the three local hapu Ngai Te Ahi, Ngati He and Ngati Ruahine, and Ngai Te Rangi and Ngai Te Ranginui iwis also attended.
Kaumatua Huikakahu Kawe reminded dignitaries and guests that the land was taken 50 years ago to for roading purposes.
"There's been many tears shed over this land, and many people have fought for its return.
But today the children and grandchildren of those people endorse your commitment to fulfil the purpose for which this land was taken and the reason we are all here today," he said.
NZ Transport Agency Bay of Plenty manager Niclas Johansson said the Transport Agency would work closely with contractor Fulton Hogan to minimise disruption during the project. Mr Johansson said information days would be held on September 11 and 12 to explain what would be happening with the site over the next three years of construction.