All indicators need to be based on readily available data and in each local area there may be rich data sources which are not available nationally. The toolkit for measuring accessibility should therefore have the flexibility to use a wide range of local sources while making use of nationally available datasets.
National data sources identified earlier (Chapman and Weir 2008) include:
· Ministry of Transport’s New Zealand Household Travel Survey
· Land Information New Zealand
· transport provider data
· regional council commuter surveys in major centres.
These are typical of the data sources in use in most countries but it is likely accessibility indicators and data collection would need to be developed in parallel to ensure relevant data was being collected to allow the accuracy and scope of the indicators to be enhanced. Key data includes:
· electronic timetable data
· electronic databases of fares
· location data for bus stops and rail stations referenced to the timetables and fares
· databases describing the attributes of the road, footpath and cycleway network by link
Activity and people
· census of population
· census of employment
· health, welfare and other indicators of population characteristics at a fine spatial scale
· locations of all land use activities to be included
· data allowing the quality and size of activity provision to be measured, eg floorspace, turnover, number of customers.