Former Northland MP Mike Sabin had called for upgrades to the one way bridges in Kaeo and Matakohe but to little avail.
The projects were not included in National's transport election policy to fast-track some regional roading projects using a $212 million package from the proceeds of asset sales.
Mr Bridges said the funding for the 10 bridges would mostly come from the National Land Transport Fund.
Mr Bridges said replacing the bridges was logical given the development of the $1.75 billion Puhoi to Wellsford highway, which he expected to boost economic development and tourism.
"It is crucial we are ready in Northland for the influx of visitors and business the Puhoi to Wellsford highway will bring."
He said National has spent more than $750 million on state highway and local roading projects across Northland in the last seven years.
'Pork barrel' politics
Labour leader Andrew Little said National's promise to upgrade 10 Northland one-way bridges is "pork barrel and a desperate bid to win the confidence of the Northland people."
"They should have fixed up the state highways after the floods, not in the middle of a byelection campaign and they should have built more bridges long ago."
When it was pointed out that the bridges were not fixed under the previous Labour Government either, Mr Little said "we're not the local MP."
After two polls showing Mr Peters had a chance of winning the seat over National's Mark Osborne, Mr Little indicated over the weekend that Labour voters should support Mr Peters rather than Labour's candidate Willow Jean Prime.
Today he said he had not told Mrs Prime to wind back her campaign but could not ignore the polls.
"But as a campaign we are responding to the polling information that has been coming out. It's up to the voters to decide whether the byelection campaign is a chance to give the Government a message about being overlooked and neglected for so long. It's up to them to make a judgement about how best to send that message."
He said Mrs Prime would continue to campaign to highlight the issues in the electorate that Labour felt were important.
He had spoken to Mrs Prime but would not reveal what he had said, including whether he had promised a strong list spot.
Mr Little said he had not spoken to Mr Peters or any of his emissaries about his position. "There's been no messages, nods, winks, nudges, blind donkeys or anything."
Mr Peters said he did not want to comment on Mr Little's comments or the implicit nod to Labour voters to back Mr Peters. "I'm not concerned about any campaign but ours."
However, he said he would take any votes that were going. "We are grateful for support from wherever it comes because the issue at the end is sending them a message."
NZ First leader Winston Peters says Northlanders should be wary of a whether National will stick to the promises it makes in a byelection as it tries to hold onto the Northland seat.
After National announced it would upgrade ten one-way bridges in the region, Mr Peters that was because National was in shock because of Mr Peters' campaign for the seat. He said Northlanders had been asking for the one way bridges to be fixed for decades but under National it kept being pushed down the list of priorities.
"Surprise, surprise, this morning National announced it will fix 10 bridges in Northland ... soon, to quote a former Russian leader, Krushchev, 'they'll be promising a bridge where there is no river."
In a speech to an audience in Whangarei, Mr Peters said the flow of promises meant it was even more important to vote for Mr Peters or National would backtrack on those promises.
"To make National keep their promises you need someone looking over their shoulder every day, every week, every month of the next two and a half years." He said if Northlanders wanted a change in fortunes they had to vote for that change.
"A week ago they had never given any of these things a thought, now all of a sudden they are Top Priority... You are going from being jilted to the most loved voters in the country."
Mr Peters pointed to the closure of Air NZ services to Kaitaia, and a cut in Northland's regional road funding.
Mr Peters also announced his own policy - to stop the expansion of wharfs by Ports of Auckland and instead develop the Port of Whangarei's container port. "Aucklanders will not have their harbour ruined and you will get the infrastructural investment in your port. It's a win/win."
He also repeated his longstanding policy of developing a rail link to the Ports of Auckland.
The bridges covered in the new announcement
•Taipa Bridge on State Highway 10
• Kaeo River Bridge on SH10
• Waihou River (Rangiahua) Bridge on SH1N
• Tirohanga Stream Bridge on SH11
• Taheke Bridge on SH12
• Waimamaku River (Hallahans) Bridge on SH12
• Waimamaku River (Lowes) Bridge on SH12
• Darby and Joan Kauri Bridge on SH12
• Matakohe River (Hardies) Bridge on SH12
• Andersons Bridge on SH12
