it was therefore with concern over access to the plains that the canterbury provincial council, formed in november 1853, established four months later a commission to examine the options for improvement. only one road route was considered feasible, the sumner road passing under the summit of evans pass via a 350-yard tunnel. there were two contenders for the rail line: a direct route down the heathcote valley and through a 2.5 km tunnel to the lyttelton foreshore, or a more circuitous route via the avon heathcote estuary and around the shore to sumner, where a shorter tunnel would take the line to gollans bay and lyttelton.