"We're working at pace on the bigger picture and to find longer-term solutions."
When asked when he was prepared to say "enough is enough" for the future of the gorge, he said the road has been out of action "for too long".
So far the NZTA has spent $20 million on repairs to the gorge and when work on the Saddle Rd is included, this increases to $30m, but the figure doesn't include the cost to local businesses.
"Reports from 2012 suggested costs of between $120m and $1.86 billion could need to be spent on the gorge [to future-proof it]," Mr Bridges said.
Ross I'Anson, NZTA's regional transport system manager, said the cliff face is moving quickly, with one section having moved 50mm closer to the river recently and the face above having moved 80mm in the past month.
"The risk is extreme," he said. "How long it will keep moving or when it will fall?
"This is a lot worse than we were thinking and far beyond what was expected. This is a game-changer for us."
Geotechnical assessments have confirmed the entire hillside is moving and the rate of that movement is accelerating.
Grant Smith, mayor of Palmerston North City, said the latest news has taken everyone by surprise.
"There's not much to smile about, this is a moving beast," he said. "But safety is paramount and we're fortunate no one has been killed in here.
"For this whole hillside, it's not a matter of if it will come down, it's when."
Mr Smith said there's a strong sense of urgency for an alternate route but added that Ashhurst residents can't continue to have logging trucks and B-Trains going through the town.
Tararua District mayor Tracey Collis said she's very concerned at the prospect of Fonterra tankers coming on to both the Saddle Rd and Pahiatua Track at the start of the milking season.
With 20 per cent of the 7000 vehicles which previously used the Manawatu Gorge road being heavy vehicles, it's imperative Saddle Rd is made safe to handle that traffic, Wairarapa MP Alastair Scott said.
"With NZTA taking over responsibility for that road from the council we'll see activity there ASAP, because the minister has said the money is there to get on with the job."
Dannevirke truck driver Fiona Carson said she's thinking about giving up her driving job in Palmerston North because commuting on Saddle Rd each day "just sucks".
"The extra fuel consumption, plus having to get a wheel alignment done because the craters can't be avoided when you have oncoming traffic, the brake usage while on the decline sections, it's more wear on my car, the trip takes longer," she said.
"Although I don't travel over the Saddle much in my concrete truck, when I do the truck gets very, very hot climbing up, which is only going to get worse in the summer and then on the downside you are trying not to run out of air for the brakes.
"The Saddle Rd isn't a solution, it's a sad band-aid, so my fingers are crossed for a more permanent flat option, though I'm in agreement that if the gorge could take a life, then it should remain closed."
Hastings trucking company Emmerson Transport Ltd managing director Ian Emmerson said the latest news came as a shock but was a fact of life.
The company used to run about 20 unit loads a day through the gorge and has now added on a gorge closure surcharge for customers to keep up with additional costs.
"About 20 minutes gets added on to the journey one way and it is a harder road to travel due to the gradients and the bends."
Like Ms Carson, Mr Emmerson said there needed to be a solution and wondered if there was a vision to find an alternative route.
"If there is, then less money should be spent on improving the Saddle Rd and more should be spent on finding a more suitable route."
However Mr I'Anson said the NZTA will update Saddle Rd significantly and despite $8.5m having already been invested in upgrading the route, more work is planned.
"The significant length of the current closure has put the Saddle Rd under added pressure and the Transport Agency will be working to upgrade the road and keep it safe. The reality is that the Saddle Rd will effectively be functioning as the state highway connection for this part of the country for some time."
With regard to the Bay's economy, Hawke's Bay Chamber of Commerce CEO Wayne Walford doesn't see the closure having too much of an effect, with a lot of freight travelling via rail to and from the port.
"The freight network should be okay with the use of rail but I think the closure means we should start to look at other options such as coastal shipping, but this all depends on the Wellington Port situation."
Mr Walford said it would be interesting to see what would happen and where people were happy to invest their money.