Assessing Equitable Accessibility Based on Total Travel Cost and Multiple Options: Case Study of Airport Ground Access in Hong Kong

In recent decades, transit equity has become a recurrent topic within the domain of sustainable transportation, where accessibility is a crucial indicator. However, the measurement of accessibility and equity in existing studies is usually based on the route with the shortest travel time, whereas multiple travel routes and corresponding travel costs remain unexamined. Taking the ground access to Hong Kong International Airport (HKIA) as an example, this study aims to fill the previous research gaps by examining the equity of accessibility by public transport simultaneously considering different sets of route options and corresponding total travel costs. These routes have either the shortest travel time or the maximum time-saving benefit-monetary cost ratio. Results reveal spatial variation in the total travel cost, which reflects considerable horizontal inequity. The results, however, indicate that vertical equity exists because the total travel cost is positively correlated with median income level across different locations. In addition, the route that provides a reasonable benefit-cost ratio further improves the equity in accessibility to HKIA. The study illustrates the significance of simultaneous consideration of total travel costs and multiple routes in the assessment of accessibility equity. It also provides transferrable methods for evaluating transit equity.