 The route north of Wellington known as the "Centennial Highway" from Ngauranga to Pukerua Bay and Paekakariki had been started in 1936 and was opened on 4 November 1939; the section north from Pukerua Bay is along the coast and below the Paekakariki escarpment.Supporters claimed that it will improve access to Wellington City, arguing that the existing coastal route is too congested, is accident-prone, and could be damaged in a serious earthquake.Peter Dunne, MP for Ohariu, says that "[i]mproving Wellington City's northern access and egress is a vital key to the future economic performance and prosperity of the whole region, and the Transmission Gully highway is a vital link in that chain".