The Main North Line was built to serve many purposes: to provide suburban passenger services to Christchurch; transport rural settlers and their produce from agricultural areas to the north of Christchurch; and eventually provide a link to the areas of Marlborough, Nelson and the West Coast. For many years debate raged as to the best route for the railway to connect with Marlborough, with two lines extending north from Waipara. Eventually the coastal route was chosen and the Cheviot Branch (which actually terminated in Parnassus) was extended north to meet the line from Picton at Kaikoura in 1945 while the Waiau Branch's importance declined.