City Rail Link


Auckland Transport



Completion date

est. 2024

Auckland’s City Rail Link (CRL) Project is a twin 3.4 km underground passenger railway from the heart of the CBD to the inner suburbs. The $2.5 billion project incorporates two tracks in separate tunnels, two new underground stations, and upgrading of two existing stations - including the iconic Britomart Transport Centre. The project is estimated to complete in 2024.

Our Brief

Marshall Day provided noise and vibration expertise for the construction and operation of the Project, preparing the Assessment of Environmental Effects, Construction Management Plans, and expert evidence at three hearings including the Notice of Requirement at which the Project was granted consent.

Marshall Day then continued working during the appeals phase, participating in Environment Court mediation hearings and expert conferencing, as well as stakeholder management.

In the Reference Design phase Marshall Day provided the station acoustic, sound system, building acoustic, construction management and mechanical services expertise for the new and upgraded stations.

In addition to the principal works on the railway, Marshall Day has also provided assessment and expert evidence at two further consent hearings and are currently engaged in the Contractor design and construction phase.


The key challenges of the CRL Project have included managing construction effects on major stakeholders including highly sensitive acoustic environments (recording studios, hotels, residences) and caucusing with other experts to achieve robust and reasonable outcomes.

Noise and vibration were two of the key issues during the consenting stage and our involvement was instrumental in obtaining consent for the Project to proceed.


Facilitating a landmark public transport Project like this benefits the entire Auckland region – particularly users of the rail network. Traffic volumes on the road network will also ease as CRL provides a real alternative for moving to and from the Auckland CBD. Also, with our acoustic design of the stations, CRL patrons will enjoy a station environment with less noise from public congregation and train arrival/departures, and public address announcements that are easily understood.

A pragmatic approach to construction management, and adoption of robust design and assessment criteria for rail noise and vibration. Our experience at Environment Court level enabled us to work constructively at the hearing, mediation, expert caucusing and public consultation sessions, which was key in enabling the Project. Our knowledge of construction noise and vibration issues has been valuable in designing monitoring and management to minimise effects.