Dunedin Northern Motorway near Waitati. An extensive section between Allanton and the Taieri River was realigned during the 1970s. Former spurs SH 1A ran from Orewa to Silverdale. When the Northern Gateway Toll Road opened, part of SH 1A was incorporated into SH 1N and the rest had its highway status revoked. SH 1F was the name previously given to the northernmost section of SH 1N – between Cape Reinga and the junction with SH 10. This section is no longer a spur and is now part of SH 1N. Where SH 1 has moved onto a bypass, sometimes the former route is designated a spur until such time as the road can be transferred to the local council. All these routes are unsigned and appear as local arterial roads on maps. SH 1D was assigned to the former SH 1S route between Abbotsford and Saddle Hill in southern Dunedin, via the suburbs of Sunnyvale and Fairfield. The route was the bypassed Fairfield section of the Dunedin Southern Motorway in 2003. SH 1G was assigned to the former SH 1N route between Taupiri and Horotiu via Ngāruawāhia. This section was bypassed by Waikato Expressway in December 2013. SH 1J was assigned to the former SH 1S route through Belfast. This section was bypassed by the Western Belfast Bypass in December 2017. SH 1K was assigned to the former SH 1N route between Raumati and Peka Peka via Paraparaumu and Waikanae. This section was bypassed by Kāpiti Expressway in March 2017. SH 1P was assigned to the former SH 1N route between Peka Peka and Ōtaki via Te Horo. This section was bypassed by Kāpiti Expressway in December 2022. Future improvements State Highway 1 has been earmarked for several motorway projects most of which have surfaced from the National government's Roads of National Significance package announced in 2009. Northland The section of Marsden Point to Whangārei is to be upgraded to four lanes as part of the New Zealand Upgrade Programme. Auckland The Puhoi to Wellsford motorway (Ara Tūhono) is one of the projects of the Roads of National Significance. This planned new road is also referred to as the "Holiday Highway" as the current SH 1 becomes heavily congested in holiday periods from holidaymakers travelling to and from Auckland in the summer holiday season and public holiday weekends. Construction of the Puhoi to Warkworth section began on 8 December 2016