There will also be some restrictions on Tamaki Dr from 5am to 1pm.
"The roads surrounding the race will be monitored throughout the day to ensure disruption is minimised," said AT spokesman James Ireland.
"We want drivers to make sure they stay safe and be patient. We realise this can be a challenge but all the detours will be signposted and we're confident it will all go smoothly."
Ireland said anyone intending to go into the city tomorrow should plan ahead and think about taking public transport.
The northern busway on the Harbour Bridge would be completely closed between 4am and 11am, as would the southbound lanes one and two of the Northern motorway between Esmonde Rd and Shelly Beach Rd.
The Onewa Rd and Current St on ramps as well as the Shelly Beach Rd on ramp would be closed between 4am and 11pm.
The Fanshawe St off ramp would also be closed between 2am and 3pm.
A full list of road closures and parking restrictions can be found on AT's website.
Several bus routes, including the city link and sky bus, would be diverted during the race between 5am and 3pm.
Nearly 1000 volunteers will be helping out on the course tomorrow, helping hand out 15,000 litres of Powerade in 175,000 cups.
6000 road cones and 3000 metres of barrier fencing would help mark out the course.
And as the race goes on, 12 Kiwi families will be watching things unfold with a bit more interest than usual.
The winners of the ASB Auckland Marathon's Run Down The Rate campaign will receive a market-leading home loan rate to match the winning time at the marathon.
Last year's Auckland Marathon title is held by Aaron Pullford, who crossed the finish line in two hours, 27 minutes. If a runner repeats that effort this year, this would make the home loan rate 2.27 per cent.
On that rate, each of the 12 recipients could potentially look to save themselves up to $23,683 in home loan interest repayments.