New lanes and lower speed on SH20B to improve travel choices and safety


A reduced speed limit and new priority lanes for buses and vehicles carrying three or more people are to be implemented on State Highway 20B after public consultation showed strong support for the changes.

The changes will take effect in April 2021 once Waka Kotahi NZ Transport Agency completes the necessary formal and legal processes. By then, the road improvements part of the project will be completed with just some landscaping and minor works to finish. 

Waka Kotahi National Manager Infrastructure Delivery Andrew Thackwray says it’s very pleasing that last years’ public consultation showed such strong support for the speed review, with particularly good support for reducing the speed limit from 100 km/h to 60km/h from the Manukau Memorial Gardens to 300m west of Orrs Road.

Currently, there are three different speed limits (50, 60 and 100km/h) along the 3km stretch of SH20B between Pūkaki Creek Bridge and the SH20 interchange where most of the time the average vehicle speed is less than 60km/h.

“Considering all technical assessments and consultation feedback, the existing speed limit of 100km/h is not a safe or appropriate speed limit for SH20B and reducing it to 60km/h will provide a much safer road environment.”

The speed review is part of Waka Kotahi’s commitment to help deliver Road to Zero, the government’s road safety strategy for 2020-2030, which aims to reduce deaths and serious injuries on our roads by 40 percent over the next 10 years. 

The SH20B improvements project has widened the road, added new combined bus/T3 lanes as well as new walking and cycling facilities and new intersections to make the busy state highway safer for everyone who uses it.

The new bus lanes between Pūkaki Creek Bridge and the SH20 and SH20B interchange will support electric-powered buses providing a frequent service between the airport, Puhinui rail and bus interchange and Manukau.

“The dedicated bus lanes and the shared paths for walking and people on bikes provide more transport choices for people living in communities along SH20B for getting to the airport and to work, schools and the shops. Auckland Transport’s new electric buses will help reduce carbon emissions, which is good for people’s health and the environment.”

Vehicles carrying three or more people will also be able to use the bus/T3 priority lanes, which will help improve efficiency, ease congestion and provide reliable journey times.

Andrew Thackwray says there was strong public support for the combined bus and T3 lanes to prioritise public transport and offer travel choices like car pooling.

The SH20B upgrade  is part of a wider programme of works called the Southwest Gateway to improve travel choice around southwest Auckland and the airport. The programme is being carried out by Waka Kotahi, Auckland Transport and Auckland Airport.

For more information on the project, visit:

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