Auckland rail passengers will have to use other transport this Matariki weekend

The full rail network's closed until Sunday, as City Rail Link will be connecting its signalling systems - a railway's version of traffic lights - into the existing one.

Replacement buses are in place.

Chief Executive Sean Sweeney says a huge amount of testing needs to be done before it's safe to use.

He says it'll be the most complex and uncertain part of the project -- heading into a phase filled with unknowns they have to learn to deal with.