Complex sentence: Springs Junction has seen a major increase in traffic flows since the 2016 Kaikoura earthquake closed the main State Highway 1 route as it is located on the alternative route from Picton to Christchurch.
Split into simpler sentences: Springs Junction has seen a major increase in traffic flows since the 2016 Kaikoura earthquake. The earthquake closed the main State Highway 1 route and Springs Junction is located on the alternative route from Picton to Christchurch.