The Minimum Energy Transport Activity Access Model
A reduction in the energy intensity of private transport is necessary to manage the uncertainties of future availability of oil supplies. The built environment and transport infrastructure of an urban form will determine the extent to which low impact adaptations to these constraints are possible, and hence the resilience of residents to fuel price shocks and constraints. This paper introduces the concept that the underlying geographic form of an urban area and its transport networks is characterised by an Active Mode Accessibility that could service some proportion of the resident transport activity system. The active mode accessibility is a non-dimensional measure of the proportion of trips that can be reached by active modes, given the population demographics of the study area. Greater active mode accessibility implies greater resilience to shocks and constraints. This paper introduces a spatial method for measuring the active mode accessibility within a selected study area, a GIS-based tool for applying the method, and presents two case studies. Model results and analysis are relevant to the redevelopment of existing areas and during the planning of new developments. The Central Christchurch study presents an Active Mode Accessibility of 100%, as there are a wide range of local facilities available for every activity. The study of Rolleston township presents a significantly lower Active Mode Accessibility of 62%, due to a lack of local facilities for many activities, and in particular, education. Although the model is still under development, it clearly indicates that it is not the distribution of facilities, but the lack of local pre-school and secondary education facilities which drastically reduces the resilience of Rolleston. The high facility density of the central city, for all activities, indicates that the residents of the central city area are extremely resilient to both fuel price shocks and constraints.