By incorporating the economic costs, real and perceived, of travel into the network models, it would be possible to compare modes based on generalised cost. This would also enable the investigation of socio-economic status on accessibility, and vice versa. This is consistent with the development of behavioural economics theory and approaches to address the weaknesses of current normative economics – not least the distributive and social aspects where accessibility planning adds particular value.
Developing a network cost model would need to account for the cost of a person’s time, vehicle operating costs, interchange costs, safety and amenity costs and the economic savings due to the health benefits of walking and cycling as well as many other factors.
Incorporation of economic costs into the model would make it possible to calculate the economic benefits of various scenarios. This would then enable the formulation of benefit–cost ratios so intervention scenarios could be compared.