NZTA says the highway is down to one lane in both directions between Pukerua Bay to Plimmerton because of a slip.
Wellington's Metlink is warning those using public buses between Waikanae and Plimmerton to expect the journey to take extra time today.
Buses would limited and because of lane closures they would not be running to a set time table.
Wellington Emergency Management said State Highway 58 (Haywards Hill) between Paremata and Hutt Valley remained closed this morning.
A number of slips have also closed Takarau Gorge Rd, between Johnsonville and Makara Beach.
A slip has blocked South Makara Rd south of the golf course and a section of Shelly Bay Rd south of the old Air Force base.
It was expected take a few days to clear but the road was open on either side of the slip.
In the CBD one lane of Featherston St has reopened to traffic but a section of Molesworth St remains closed, where a structurally damaged building is threatening to topple on neighbouring property.
"Our priority overnight has been on securing the area around [61] Molesworth St that is cordoned off between Hawkestone and Hill streets, due to the building that has been structurally damaged," said Wellington city controller Simon Fleisher.
An exclusion zone has been set up around the building with cordons at Molesworth St intersections at Hill and Hawkestone Sts.
A number of buildings close to 61 Molesworth Street are off-limits to occupants and the public.
Affected buildings include:
• Royal Thai Embassy
• New Zealand Rugby Union headquarters building and the tenancies within, including NZ Post and Audit New Zealand
• Red Cross offices
• Wellington Cathedral of St Paul
A number of private houses accessed off Collina Tce have also been evacuated.
Alternative arrangements are being made for worshippers at Wellington Cathedral of St Paul, which is now formally closed.
Concerns about another building in Wellington early this morning turned out to be a false alarm.
A building at 40 Taranaki St was cordoned off just after 2am.
Fire Service shift manager Jan Wills said the building was checked after someone from Calendar Girls reported creaking and hearing loud cracks.
Fleisher also warned of peak-hour traffic delays this morning and asked people to stay out of the CBD if possible.
Meanwhile, Wellington commuters still face problems getting to work this morning because of disruptions to rail services due to flooding and slips.
Services on the Kapiti line are running a reduced timetable and all services between Plimmerton and Waikanae have been cancelled.
