Auckland buses will start using a new dedicated lane on the Northern Motorway early next month.
Transport authorities said the new lane aimed to make it faster for the 130 buses that travel across the Auckland Harbour Bridge from the city centre every hour during peak times.
The new lane will be created on the Northern Motorway, from just north of the harbour bridge to the Esmonde Rd turnoff.
"The Government and the Transport Agency have made improving public transport a priority so this project will help speed up peak time bus journeys," the NZ Transport Agency's Charles Ronaldson said.
This will encourage "more people to leave their cars at home and use public transport", he said.
Work to create the north-bound bus shoulder lane will be in two stages, starting at night on Sunday.
Buses will start using a section of the lane from December 7, and it will be fully operational from December 13.
Ronaldson said the new lane aimed to make it easier for buses during peak hour.
"When traffic is light, buses can still travel in the main traffic lanes with other vehicles," he said.
"But in peak time, when there's heavy congestion and traffic is backed up, bus drivers can opt to use the shoulder lane.
"It will mean quicker and more reliable journey times for bus passenger during peak time."
North Shore Ward Councillor and planning committee chairman Chris Darby said the new lane is a "smart move designed to maximise and increase travel time benefits for people choosing public transport".
Auckland Transport's Stacey Van Der Putten said passenger journeys on North Shore bus routes had increased by 12 per cent over the past year.
"At the end of September, the new bus network provided 44 per cent more bus service on the North Shore," she said.
"By providing a dedicated lane for buses between the Harbour Bridge and Esmonde Rd, this will mean that no matter how busy the traffic is, bus passengers can get where they need to go easily and on time."
Buses travelling over the harbour bridge heading north currently use sections of the motorway shoulder but have to merge in and out of the left hand lane as they pass the off and on ramps at Onewa Rd.
Now they will be able to use the marked bus-only shoulder lane for an uninterrupted and quicker journey.
As they pass the Onewa Rd onramp, buses will merge with vehicles approaching from the left.
At Esmonde Rd off ramp, one of the three right turning lanes will become a dedicated bus lane.
For the safety of all road users, buses will travel at less than 60km/h in the shoulder lane as they pass slow-moving or queuing traffic.