A 4km section of Auckland's Northern Motorway will be closed five nights a week for the next four months, starting tonight. The NZ Transport Agency (NZTA) says the motorway will be closed between Upper Harbour Highway/Constellation Dr and Oteha Valley Rd from Sundays to Thursdays between 9pm and 5am. NZTA advises motorists to allow more time if travelling at night on the Northern Motorway in coming months. The closures will allow crews to start preparations for the Northern Corridor Improvements (NCI) project, a new link between State Highway 1 and State Highway 18 due to start later this year. They will be resurfacing the motorway, painting new line markings and moving median barriers and overhead gantry boards, says the agency's senior manager project delivery, Chris Hunt. The repainted lanes will be narrower, so as the work progresses along the 4km stretch of motorway, the speed limit will be reduced to 80km/h. "The work is being carried out at night to reduce disruption and delays on the roads and motorway during the busiest parts of the day. Closing the motorway ensures the safety of our crews working at night and all other road users," says Hunt. The closures will apply to all lanes and the on- and off-ramps between the two interchanges, including all ramps at the Greville Rd interchange.