$415 million electricity supply improvements likely to cause delays for city-bound motorists.
Buses normally allocated their own lane along one of Auckland's heaviest commuter routes will have to vie for space with cars during months of post-Christmas roadworks in Fanshawe St.
The city-bound bus lane between the Northern Motorway and Nelson St will be opened to general traffic while the road is narrowed between next week and March to make way for a $415 million electricity supply upgrade for Auckland and Northland.
Although two lanes will remain available to traffic from December 27, commuters from the North Shore will be urged to avoid delays by using the motorway's Cook St or Grafton Gully exits to reach downtown Auckland.
Electricity grid operator Transpower, which is laying a high-voltage supply line from Pakuranga to Albany via the Northern Motorway, will also take advantage of lighter summer traffic to close both city-bound lanes of Waipuna Bridge in east Auckland until January 13.