Almost 14,000 people are set to pound the pavement in the Auckland marathon tomorrow.
The country's biggest road race will see a number of roads closed and diversions put in place around Auckland CBD and the North Shore, including parts of the Harbour Bridge.
The marathon course starts in Devonport and heads through Takapuna before going south over the Harbour Bridge. The course then continues along the waterfront and Tamaki Drive to St Heliers, where participants will turn around and head for the finish line at Victoria Park.
The Northern Busway, between Constellation Dr and Onewa Rd interchange, was set to be closed from 4am on Sunday until 11am, as would southbound lanes one and two of the Northern motorway from Esmonde Rd to Shelly Beach Rd.
The Onewa Rd southbound on-ramp, northbound Curran St on-ramp and Shelly Beach Rd off-ramp would also be closed during these hours. The Fanshawe St off-ramp city bound would also be closed from 2am to 3pm, other than the right hand turn into Beaumont St.
A number of roads were also set to be closed in and around Takapuna, Devonport, St Mary's Bay, Westhaven, Wynyard Quarter, Victoria Park, Viaduct Harbour, CBD, Mechanics Bay and the Bays. Detours would be in place.
Motorists could expect parking restrictions in these areas as well, from as early as 2pm Saturday through to 2pm Sunday.
A full list of road closures and parking restrictions can be found on the Auckland Transport (AT) website.
AT spokesman James Ireland said people need to plan ahead.
"If you are taking part in the marathon, make sure you check which transport option suits you best."
For participants coming from the North Shore, there will be buses to the event from the Albany park and ride, the Constellation park and ride and from 488 Lake Rd, Takapuna.
If you're coming from the city there will be ferries running from 4.20am, leaving the Downtown Ferry Terminal.
After the race, Northern Express buses will leave every 15 minutes from Victoria Park, and ferries and trains will be operating.
There was also set to be some changes to bus stops and services along the route, including the Northern Express, CityLink and SkyBus. Bus stops would be reopened during the day as the course becomes clear.
Ireland warned bus users should expect some delays.
Participants from 49 countries including Australia, the UK, United States, Germany and China will be lining up at the start this year.
Almost 700 runners have signed up to run for charities including the Mental Health Foundation, Cancer Society, SPCA and Auckland City Mission.