A methodology for prioritising possible suburban public transport interchange locations was developed prior to the devastating Canterbury earthquakes of September 2010 and February 2011. A number of measures were included to inform the implementation priority of suburban interchange sites throughout Christchurch.
One measure was based on the potential coverage area for passengers travelling through any interchange site in the peak period from 3pm – 6pm. The method took account of the number of bus services and frequency at each site and calculated travel coverage area over a fixed period of 20 minutes, which included waiting time. The measure assumed a person arrived at an interchange without knowledge of the bus timetable. Waiting time was calculated based on the average person typically waiting for half the service frequency (ie some people arrive just before the bus leaves, others just miss the bus). The speed of travel on the road network was set to the Environment Canterbury (ECAN) target of 26km/h for travel on bus services in peak periods.
Locations such as Westfield Riccarton and Christchurch Public Hospital scored highly on this measure. Suburban shopping centres such as the Palms, Bush Inn Centre and New Brighton were the next highest rated on this measure but these were rated considerably lower than the first two sites. Christchurch airport, Princess Margaret Hospital, and suburbs such as Lyttelton, Bishopdale and St Martins scored poorly against this measure.
The measure, although not strictly an accessibility assessment (ie measuring ‘opportunity’), did make use of a number of the elements that would inform an accessibility assessment including walking and public transport networks, bus-stop locations and service frequencies.