The latest project update from the CNC Alliance contains information on noise effects of the motorway and possible mitigations. All the noise mitigations required for the project are now in place, with the exception of the final asphalt layer on the road. Work to apply this on the motorway and QEII Drive will begin in Spring 2021, and is due to be finished in early 2022. Click through to read the full update:
https://www.nzta.govt.nz/assets/projects/christchurch-northern-corridor/CNC-project-update-finishing-touches-20210326.pdf