The NZ Transport Agency urged commuters to be prepared for significant delays and disruptions tomorrow morning.
The power outage that hit Auckland today is expected to continue to affect the operation of traffic lights, ramp signals and electronic messaging signs.
Generators were being dispatched to a number of key intersections, and police would be assisting with points duty at others, but the scale of the disruption meant that some intersections were likely to be without power or points-duty control in the morning, NZTA spokesman Andrew Knackstedt said.
Motorists were advised to consider alternate transport modes, and whether they could go to work late or work from home, he said.
Where intersections were not working, motorists were asked to remember the give way rules and drive with extra patience and caution.
Sections of the motorway and arterial roads would not have street lights while the outage persisted, Mr Knackstedt said.
Motorists can check the latest conditions here.
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Despite the concern, fewer crashes have been reported in Auckland during the traffic-light outage.
Auckland Police Communications Shift Inspector Peter Raynes said there had been no traffic incidents in areas affected by the outage.
"There's actually been a reduction in traffic crashes reported to police communications. Clearly the public are obeying the road rules."
Police were on "points duty" at major intersections where traffic lights were down due to the outage, Mr Raynes said.
"Most of the motorway on and off ramps from Mt Wellington towards Otahuhu are manned and the critical incident ones around Penrose."
Auckland police also encouraged homeowners and business owners to take extra security precautions wherever possible as some alarms may be affected, Waitemata police relieving communications manager Katherine Manaton said.