The New Zealand Transport Agency is warning of long delays for people travelling on Auckland's northern and north-western motorways this weekend because of construction.
Work is underway Saturday and Sunday at two busy sections - the Te Atatu interchange and the Greville Road interchange.
The agency's highway manager, Brett Gliddon, said drivers should avoid the two areas.
Mr Gliddon said, during weekends, about 6000 vehicles an hour use the Te Atatu overbridge or the motorway beneath it.
He said the interchange would not cope with that volume of traffic while the work was being done.