Methodology validation

The accessibility methodology has been calibrated using behavioural characteristics such as inputs from the NZHTS. It is a typical process for model outputs to be validated against an independent set of data. Validation of the accessibility outputs resulting from the research methodology has not been undertaken although there was always an expectation the output of the methodology would be confirmed by community perception surveys. The methodology for undertaking this work, including the source for the independent set of data, and the basis for the validation eg time, cost or a combination of both, should be developed. It may be that the accessibility results could be tested against say, journey-to-work mode split data although the results would have to be used cautiously because mode split data reflects what people ‘would’ do, and not what people ‘could’ do.