Eight other roads have been ranked as nationally significant including the road through the Manawatu Gorge.
Mr Bridges said the decision on the Tauranga to Katikati road was based on population growth and because it was one of New Zealand's most treacherous roads, with 18 deaths in four years.
"Four-laning will make it hugely more forgiving," he said.
Bay of Plenty MP Todd Muller said the four-laning would transform this end of the Western Bay by enabling more people to live there and set up businesses.
"There will be a huge influx of businesses and people to take advantage of a very strong arterial highway linking to Tauranga and the port. Tauranga is a hub city ... for the next decade we will be investing an extraordinary amount of money."
Yesterday's announcement was effectively about four-laning from Omokoroa to Katikati. This was because the Government had already decided to spend up to $600 million to build the Northern Link bypassing Bethlehem and Te Puna, four lanes from the end of the link to Omokoroa, and to build the Katikati bypass.
Western Bay's Mayor Garry Webber said it was more cost effective to continue with the rest of the route to Katikati once the four-laning had reached Omokoroa, rather than contractors coming back year after year and "nibbling away" at improvements like passing lanes.
Mr Webber said the four-laning was important in the context of what drove Western Bay's economy - horticulture including kiwifruit and avocados, agriculture and forestry.
With kiwifruit volumes forecast to double in 10 years and forests in the Coromandel Peninsula approaching harvest, it added to the importance of the road as a major freight corridor to the port.
There was also predicted to be a 27 per cent increase in kiwifruit truck movements to the port caused by the trend towards the containerisation of kiwifruit, he said.
"My hope is that whoever is elected, they will put this announcement into practice."
The Labour Party candidate for Tauranga Jan Tinetti said it was good that the Government was recognising roading issues around the Tauranga area, but it had to look beyond building more roads as the solution to transport problems.
They had to look at reducing traffic congestion between Tauranga and Katikati by getting more people into alternatives like public transport.
Bay of Plenty Regional Council's regional transport committee chairman Stuart Crosby said the announcement was great news and would give the New Zealand Transport Agency the confidence it needed to plan ahead.
However, with the National Party not fulfilling its 2008 pre-election pledge to fund the whole of Tauranga's central corridor project, people could get cynical about election pledges.
Mr Bridges was asked whether some people might see the announcement as an election bribe. He said that not long after the first of the National Roads of Significance were announced, he said there would be a next generation of roads of significance, and these were the logical next steps.
The great importance was the certainty and priority it gave to the road from Tauranga to Katikati, he said.
Aongatete Coolstores' coolstore manager Stan Johns said it would be good to see the road four-laned, with a median barrier.
The left-only exit would prevent the type of manoeuvre that killed five workers when their car was hit by a truck last year as they attempted to turn right towards Katikati.
It meant traffic leaving the coolstores and wanting to head north would have to change direction at the next major south-bound intersection, unless a grade separated intersection was planned for beside the coolstores.
Mr Muller said the size of the investment and the staging of the works over the 10 years had yet to be decided.
Tauranga to Katikati road upgrade
- Four lane highway with median barrier
- Wide lanes and sealed shoulders
- Mainly grade separated intersections
- Safe roadsides clear of obstacles and ditches
