Evaluation of Public Transport-Based Accessibility to Health Facilities considering Spatial Heterogeneity

Table 1

Comparisons of the four accessibility measures [9].

Accessibility measures	Description	Formula	Advantages	Disadvantages
Travel-cost approach	The ease with which any land-use activity can be reached from a location using a particular transport system		(i) Quite easy to understand and to calculate; (ii) Less demanding on data	(i) Neglects variations across individuals; (ii) Highly sensitive to the choice of demarcation area; (iii) Neglects variations in the locations
Isochrone approach	The number of opportunities that can be reached within a given travel time, distance, or generalized cost		(i) Relatively easy to understand and to calculate; (ii) Easy to visualize	(i) Neglects variations across individuals; (ii) Highly sensitive to the size of the range and the representation of opportunities; (iii) Neglects variations in the locations
Gravity-based approach	Potential of opportunities for interaction		(i) Able to differentiate between locations; (ii) Represents the joint effect of transport systems and land use patterns on accessibility	(i) Neglects variations across individuals; (ii) Ambiguity regarding the magnitude of indicators
Utility-based approach	Expected maximum utility from a random utility considering individual characteristics		(i) Captures individual differences; (ii) Captures the impact of all modes including auto, transit, and nonmotorized options	(i) Demands extensive data on locations and individuals’ travel behavior

Note: A_i represents the measure of accessibility at location i, n represents the number of included locations, f(c_ij) represents the deterrence function and c_ij represents a variable that represents travel cost between locations i and j, c∗ represents the predetermined threshold within which the activity opportunities are counted, N_j represents the opportunities in a zone j, represents the utility of group n selecting the alternative, represents some measure reflecting the attraction of the alternative j, and represents a positive scale parameter.