The Transport Agency says it remains optimistic that two of the lanes in Auckland's new Victoria Park tunnel will be completed by Monday morning.
Final work on the $340 million project, which connect northbound lanes to State Highway 1, is under way.
From just north of the Nelson St off-ramp, traffic has been reduced to one northbound lane this weekend, and the road will close altogether overnight on Saturday and Sunday nights.
Transport Agency spokesperson Andy Knackstedt says work is progressing well, but motorists need to avoid the area because of heavy congestion.
Police say there have been no traffic problems on Saturday.