Over the next 10 days, 60,500 people will get to walk and cycle inside the tunnel, which used 24,000 concrete segments to line the walls, 140,000sq m of paint - black for the roof, white for the walls - 4000 lights and 400km of cabling and wiring.
At 2.4km long, Waterview takes the record off the 1.97km Lyttelton tunnel as the longest road tunnel in New Zealand.
On Monday evening, a champagne and canape Toast the Tunnel event will be held inside the tunnel to raise funds for the Cancer Society. Tickets cost $285.
As well, a film called Motorway has been made about the project. Starring Wallace Chapman, it looks at the Waterview community and the push for the motorway to be built.
Watch the trailer below.