 The first section of the Johnsonville–Porirua Motorway opened in December 1950 but traffic was funnelled through Johnsonville until a bypass was completed towards the end of the 1950s joining the Gorge's four lanes to the Motorway.A junction controlled by lights remained between the two highways until the end of the 20th century.During the 1960s the road through the gorge was widened from four to six-lanes.