Plan to ease congestion on Christchurch’s Northern Motorway to go ahead

Environment Canterbury’s council today approved a variation to the Regional Land Transport Plan to allow a third southbound lane, and a cycle facility, over the Waimakariri Bridge to address congestion.

The recommendation to vary the plan was made in August by the Canterbury Regional Transport Committee, on the basis that the third southbound lane will operate as a high occupancy vehicle lane during the morning peak, and that a new cycle lane is attached to the bridge.

Environment Canterbury acting chair Steve Lowndes says the construction of the third lane will help improve travel time reliability along this section of Christchurch’s Northern motorway. The shared cycle path addresses safety concerns across the Waimakariri Bridge for cyclists and pedestrians.

“The high occupancy vehicle lane will be a first for Christchurch, and will encourage motorists to think about how they travel – carpooling, public transport use and cycling will all be promoted alongside the construction of the third southbound lane and cycle facility.

“The NZ Transport Agency will now develop the detailed design, with construction expected to start in 2018 and finish in 2020.  The immediate steps are to determine the exact location and length and a safe operating plan for the new lane.”

The Waimakariri Bridge Improvement variation was proposed by the Transport Agency to deliver reliability and safety outcomes, as part of the wider State Highway 1 Picton to Christchurch programme of work, identified in consultation with stakeholders.  Public consultation on the proposed variation took place between 13 June and 13 July 2017. Of the 177 submissions received, 86.5% supported the proposal.

The additional lane and cycle facility is expected to cost about $20 million and will be built as part of the Christchurch Northern Corridor project. This provides significant savings of about $14 million, compared to constructing the third southbound lane at a later date, separate to the Christchurch Northern Corridor project.

For more background information read our previous story

A copy of the report and the agenda to the Regional Transport Committee are available here: 

Frequently asked questions
Why is a third southbound lane with higher occupancy vehicle management being built over the Waimakariri Bridge?

A third southbound lane on Christchurch’s Waimakariri Bridge will help ease commuter congestion in the morning which is creating lengthy delays, long queues and unpredictable journey times. The high occupancy lane management will encourage more people to share a ride to reduce the ongoing traffic growth heading into Christchurch during the morning peak. The proposal will also reduce traffic on Main North Road and improve bus reliability on the existing bus route.

What will the changes be to Christchurch’s Northern Motorway?

The changes include:

  • A third southbound lane over the Waimakariri Bridge which will be operated as a high occupancy vehicle lane during the morning peak.
  • A shared cycle path attached to the eastern side of the Waimakariri Bridge, creating a safe cycle link between Christchurch’s major cycleway network and the cycle network in Waimakariri.

Work is underway to determine the exact location and length of the high occupancy vehicle lane.

These changes are part of a wider programme of work identified in the Transport Agency’s State Highway 1 Picton to Christchurch Programme Business Case.

What is a high occupancy vehicle lane?

With the number of trips on Christchurch’s Northern Motorway expected to grow by 25% in the next eight years and by 50% by 2041, the current 85% single occupancy vehicle use on Christchurch’s Northern Motorway is not sustainable.

Carpooling, greater public transport use and cycling – all of which will be promoted alongside construction of the third southbound lane – are core parts of the Greater Christchurch integrated transport system for travellers from North Canterbury.

When will the building commence?

The third southbound lane on the Waimakariri Bridge will be built as part of the Christchurch Northern Corridor project which is under construction and scheduled for completion in 2020. Work around the Waimakariri Bridge, including this third southbound lane, is expected to commence in 2018.

How long will it take?

The Christchurch Northern Corridor has already started construction, with work around the bridge starting in 2018 and completion scheduled for 2020.

What disruptions can commuters expect while the construction takes place?

The Christchurch Northern Corridor project will update road users and residents as this project develops. Go to for more information and to sign up for their regular newsletters.

How much will it cost?

The third southbound lane and separated cycleway over the Waimakariri Bridge will cost about $20 million. Building the lane now, as part of the Christchurch Northern Corridor project, will save $14 million compared to if the lane was built at a later date.

How will it be funded?

It will be funded by the Transport Agency through the National Land Transport Fund as a state highway improvement.

What will the impacts be on traffic volumes in Christchurch suburban areas such as St Albans?

Community impacts, especially those downstream of this proposal, will be a key part of evaluation of this project.

One of the main reasons for introducing the higher occupancy vehicle lane is the need to minimise the impacts of the third lane on the downstream Christchurch transport network in areas such as Cranford Street and Innes Road. By encouraging more people to share a ride there will be less traffic growth in the future.

Christchurch City Council (CCC) is required to employ an independent expert to develop a downstream effects management plan as a condition of the consent granted on the Christchurch Northern Corridor.

The independent expert will assess the traffic impacts of the Corridor, and design a series of mitigation measures to address these impacts. CCC will therefore make changes to the roading network in the area around the Cranford Street and Innes Road intersection (and further south) to address the traffic impacts of this work. 

Currently, CCC is planning for community engagement on this process to start at the end of 2017, with construction of any works to start before the opening of the Christchurch Northern Corridor.

Was there a public consultation on this project?

Yes – the Regional Transport Committee established a panel with an independent Chair to oversee public consultation on the proposed variation to the Canterbury Regional Land Transport Plan.

Members of the public were able to make written submissions between 13 June and 13 July 2017 with oral submissions being heard in early August.  177 written submissions were received, of which 86.5% supported the proposal. 

Will the old Waimakariri Bridge become a designated bus lane?

No decision has been made to designate the old Waimakariri Bridge a bus lane, and it is not something being considered at present.