From Waka Kotahi: SH1 Tinwald update 27 April 2023

Published: 1 May 2023

Regular updates on the SH1 Tinwald Corridor Project are being provided by Waka Kotahi NZ Transport Agency.

Plans for the highway and rail through Tinwald are progressing nicely.

We're working closely with Ashburton District Council and with KiwiRail on project phasing and procurement.

Detailed design is now complete for the road improvements with some details to be finalised with key stakeholders.

The project team has released the tender for construction work which went to market in the middle of last month (mid-March 2023).

Construction work is scheduled to start around mid-2023.

Vehicle turning retained at viaduct

During the final stages of detailed design we made some changes to the plan for Melcombe Street viaduct (opposite Carters Terrace).

Initially, we had planned to restrict vehicle movements at the viaduct to 'left turns only' onto the highway (and stopping traffic from turning left under the viaduct or turning right from the highway). After consultation with the community and further investigations, we decided to retain full access at the viaduct with monitoring.

Retaining all vehicle movements provides options for local access and reduces traffic further down the road at Compton's Crossing, the rail level crossing mid-way between Lagmhor Road and the viaduct. A number of people told us during community consultation that full access was preferred for this reason.

The design still includes a shared path under the viaduct linking to Ashburton Bridge and the South Street signal crossing.

Click here to view a map showing the highway and rail improvements and the changes made since community consultation.

Good questions keep coming

We've had lots of questions about how the upcoming changes will work over the past couple of years.

Recently, we've been asked if it's possible to have more pedestrian refuges built into the highway centre median.

Unfortunately there is not space to do this as vehicles would be prevented from turning right onto the highway from side streets and accessways.

While we were planning for this project, local feedback was that people parking on the railway side of the highway mostly cross where it is convenient. Because there are no obvious crossing points, the planned wider centre flush median through Tinwald will be an improvement, as people can walk across the two lanes of highway in stages and wait in the middle if they need to.

The safest place for people to cross will be the new signalised pedestrian crossing, once the new traffic signals are installed at the intersection of SH1/Lagmhor Road/Agnes Street around mid-2023.

This will be encouraged as the safe route to school - via Agnes and Thomson Streets.

Further south, people can also cross using the highway pedestrian refuge in the Graham Street/Jane Street block (by the RV Centre) built last year. This work is outside the scope of the NZ Upgrade Programme funded work and will stay as a permanent crossing point.

More information

For more information on the SH1 Tinwald Corridor Improvements visit our website

Got a question? Here are some answers to frequently asked questions.

Or email us

Waka Kotahi is delivering this project as part of the New Zealand Upgrade Programme - the government's $8.7 billion investment in growing communities across the country.

Visit for more information.