A stretch of Tāmaki Drive in east Auckland is only open to one-way traffic to make way for spectators viewing the America's Cup World Series.
Mission Bay's Tāmaki Drive between Atkin Ave and Ngapipi Rd will only be open city-bound until about 8pm this evening.
There are also parking restrictions in place on both sides of Tāmaki Drive.
Nearby, Paritai Drive is closed until 8pm between Okahu St and Tuhaere St, including Titai St.
There are also parking restrictions on Patterson Ave in Mission Bay.
In Devonport, all of King Edward Parade, and along Cheltenham Rd to the intersection with Tainui Rd, is closed until about 8pm, as well as Jubilee Ave, Takurunga Rd and Macky Ave.
These closures and restrictions are expected to be in place on race days from December 17-20 between 1pm and 8pm, but could change depending on the course day selection, Auckland Transport said on its website.
Congestion is expected around Ōrākei and Tāmaki Drive on race days, so motorists are advised to plan ahead and to consider public transport if possible.
The America's Cup World Series is the first opportunity for the teams to go head-to-head in official races, having squared off several times in practice duels in recent weeks.
There are five racecourses on the Hauraki Gulf and Waitemata Harbour, with selection depending on the weather conditions.
The racecourse will be selected by 10am on race days.
Today's opening day of racing is being held on course C, which runs in the waters between North Head and Bastion Point.
The racing window runs from 3pm-6pm.
The first three days follow a double round-robin format, with four races each day. Each team will face their three opponents on two occasions.
The top-ranked team from the round-robin will then face the fourth-best team in one semifinal, with the second - and third-placed teams squaring off in the other.
The winners of each semifinal will face off in the Christmas Cup decider, while the two losers will race in a playoff for third.
For Team New Zealand, it is their only chance to take on the three prospective challengers in official races before the America's Cup match next March.
Luna Rossa, American Magic and Ineos Team UK will then battle it out in the Prada Cup starting in January, which will determine who will compete against the defender Team NZ in the America's Cup match.
• Avoid traffic congestion and parking niggles and download the AT Mobile app to plot your bus, train or ferry ride to race venues before you leave home.
• Make sure your AT HOP card is in your pocket. It's the best way to ride to the Cup
• For more ways to enjoy race day, visit at.govt.nz/americascup
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