All motorway access points are now open after protesters blockaded the Cook St, Wellington St and Hobson St offramps earlier this afternoon.
But the Transport Agency said commuters should expect delays and some diversions as they head into or out of the central city. The Auckland Harbour Bridge has remained open throughout the protests and traffic is free flowing.
The agency is also advising drivers to be vigilant and aware of their surroundings as there are larger numbers of pedestrians on central city roads than usual.
"Many of them have been moving on and off the roads and walking in front of traffic. Some vehicles are also making sudden lane changes and u-turns to avoid delays."
Earlier, central Auckland grounded to a halt as trade ministers signed the TPP. All streets around Sky City Convention Centre and motorway on and off ramps leading to the central business district were blocked by protesters.
Former Green MP Sue Bradford was in a protest group that had partially blocked access to the Auckland Harbour Bridge from the city.
"We are in a blockade at the corner of Victoria Park and the Harbour Bridge," she said.
"Just about all of the Harbour Bridge is blocked off.
"But we'll keep moving. This is our third blockade today."
A spokeswoman for the New Zealand Transport Agency said only the Fanshawe Street onramp to the motorway, which provides access to the Harbour Bridge from the central city, was blocked. But traffic was free-flowing on the bridge throughout the protests.
Police forcibly removed protesters from the Cook St off ramp.
Pictures show police have been clashing with protesters, using force to remove them from roads.
The NZTA for Auckland and Northland recommended that people do not travel into the central city if possible.
Protesters formed blockades on the on and off ramps for the southern and northwestern motorways.
Small groups were blocking traffic in separate areas including the Wellesley and Albert St intersection.
Inside Sky City Convention Centre, a long table stretched along a stage with big bouquets of blue and white flowers displayed in front and a large screen, with photos of the Sky Tower, Southern Alps, and a tui in rotation with TPP logo, behind.
The agreement is designed to free up trade and investment between the countries, but has been a beacon for controversy for several years, mainly due to the secrecy of the deal, lack of public consultation and fears New Zealand's sovereignty could be diminished.
Outside the convention centre, they were gathering too.
By 10.20am, up to 1000 protesters were at the scene. Their aim? Disrupt proceedings for as long as possible. By late this morning, they were succeeding in disrupting the city.
Protest group Real Choice planned the non-violent protest and a blockade of the streets leading to the centre, hoping supporters in their hundreds would create a "TPP-free zone" and shut-down the signing ceremony for as long as possible.
The group gathered at Aotea Sq at 9am and made their way to the convention centre about half an hour later.
Real Choice spokesperson Julia Espinoza explained their motives.
"Petitions, marches and lobbying have their place; but now the TPP is being signed on our doorstep, and we feel it is time to try to shut it down and create a TPP-free zone."
Maraea Clark, dressed in the colours of the New Zealand flag, said the trade deal was a way of controlling people.
"It's not a better life for the people; it's a better life for the corporations who are wanting to take over."
A large group soon left the scene to join a blockade on Victoria St, where a young man was singing Bob Marley's Redemption Song.
The protesters had high-profile support - former All Black Piri Weepu tweeted them "Good luck but also be safe, No need to protest violently. Walk together for Aotearoa."
A larger group of those against the trade deal are expected to march from Aotea Sq down Queen St to Britomart from noon. The march is organised by anti-TPP group It's Our Future and spokesman Barry Coates said iwi, health workers, trade unionists, small business owners, actors, musicians, lawyers and academics were expected. Similar protests are planned outside parliament and the Christchurch City Council.
One thing the opposing sides shared was the need for organisation.
In support of law and order, police were outside the convention centre from early this morning; while Auckland Council told staff to work from home in case of disruption.
At the convention centre, in central Auckland, Sir Harawira Gardiner led on the 11 visiting ministers, who were called into the room by Cherie Povey.
As well as signing, the ministers will talk about their respective ratification processes - each have two years to get the deal passed domestically before it comes into law.
The ministers shared hongi in a small welcome party which included Trade Minister Todd McClay, New Zealand chief negotiator David Walker and, representing Auckland iwi Ngati Whatua, Tame Te Rangi.
After a karakia, Mr Te Rangi said he was proud and privileged to be there representing his iwi.
Mr McClay in turn thanked Ngati Whatua for their gracious welcome, as several groups would not take part because they oppose the trade deal.
He then welcomed the ministers for what he said was a "momentous occasions for all of our countries."