The availability of land use and transportation data plays a critical role in the assessment of accessibility. The difference between existing data and what is required for the assessment of neighbourhood accessibility is significant.
Data pertinent to accessibility assessment will need to be sourced from a combination of central government, local government and commercial spatial data providers.
The lack of a standardised data exchange format will slow the deployment of an accessibility assessment tool although the opportunity to create best practice formats as part of this process should be encouraged.
Datasets required to operate an accessibility assessment tool include the following:
· Parcel boundaries: if feasible, accessibility assessment for detailed areas such as single properties should be undertaken. Alternatively address points can be used.
· Neighbourhood boundaries: meshblock data boundaries are sufficiently small enough to define a neighbourhood or zone for an accessibility model. If these are too narrow ranging then area units can be used to define neighbourhoods.
· Land use or planning zones: this data will provide an indication of where activities take place and also allows neighbourhood boundaries to be defined by land uses.
· Land-activity use: either defined by individual properties or by point data, land-activity data is essential in defining the origin and opportunity destination locations.
· Road network data: this should include both road centreline data and features associated with the network such as turning restrictions, speed limits and traffic flow direction information.
· Walking and cycling routes: these should include travel times. Compared with road data, walking and cycling routes often allow access to spaces that motor vehicles cannot reach. This data is essential for making accessibility comparisons between different modes of transport.
· Public transport data (including public and private operators): this should include routes, stop locations, time table information and fares.
· Existing travel data: the identification of key trips currently undertaken will help aid the formulation of core accessibility indicators.
· Demographic data by meshblock: this is essential for identifying where the population lives and identifying population groups by location.
The latter two bullet points are essential information required for developing accessibility indicators.
Other datasets that would be beneficial for inclusion in accessibility assessments include:
· provisions for those with physical disabilities on public transport facilities
· hours of operation of land use activities
· quality of the walking/cycling environment
· other key deterrence factors to access including safety, security, information provision and physical features or barriers.
The following subsections discuss data availability from various sources including government-owned data, commercial data products and data available at no charge.