SH 1 passes through Amberley and Woodend before becoming the Christchurch Northern Motorway and bypassing Kaiapoi to the west. At The Groynes west of Belfast, the motorway narrows to a four-lane divided arterial. SH 1 continues around the north-western urban fringe of Christchurch, passing just east of Christchurch International Airport. At Hornby, the highway turns south-west, narrows to a two-lane undivided road and passes through Templeton. It then merges onto the Christchurch Southern Motorway where the highway becomes expressway standard until it approaches Rolleston.