The NZ Transport Agency is closing the Lyttelton Tunnel to install a new $29 million fire protection system in the tunnel.

The closures will take place between 11pm and 4am on the 26th, 27th, and 28th of August.

The three nights of closures are the first in a series of night closures in coming months to enable the fire protection system to be safely installed and tested.

A 90-day schedule of closures can be viewed here.