Auckland Transport says a new busway for South East Auckland will attract more than 5.5 million users a year.
The 7km route, announced Monday afternoon, will link Panmure train station with Pakuranga and Botany.
Buses will have separate lanes to other motorists, in an attempt to dramatically reduce congestion.
A new Panmure Bridge will be built for the busway as well as a new station in Pakuranga.
Auckland Transport expects 5.5 million passengers a year, compared with the 2.2 million using the Northern Busway, which links Auckland city to the North Shore.
Construction will begin in 2015, dependant on funding and consents.