 The road up the gorge was transformed between July 1938 and November 1939 as an extra part of the Wellington to Paekakariki project later dubbed the Centennial Highway.In June 1938 Bob Semple, Minister of Works, announced the administration of Ngahauranga Gorge would leave Wellington City and Suburban Highways Board and join the new system of State Highways.He said "Motoring mishaps, some more serious than others, are not uncommon, due principally to the tortuous nature of this road and the density of traffic which amounts to between 3000 and 4000 vehicles per day.