Balancing Efficiency and Equity in Urban Air Mobility Vertiport Siting: A Value-of-Travel-Time Approach

Urban air mobility (UAM) has been regarded as a promising way to relieve urban congestion, but its deployment depends on costly vertiport infrastructure. Since residents’ willingness to pay for travel time savings varies across urban space, market-oriented vertiport siting may lead to uneven accessibility. To examine this issue, this study develops a UAM vertiport siting framework that incorporates residents’ value of travel time (VTT) into infrastructure location decisions. Housing prices are used as a proxy for spatial differences in willingness to pay, and an average relative VTT indicator is constructed based on a VTT-housing price elasticity parameter. A mixed-integer programming model is formulated to determine vertiport locations, capacity types, UAM adoption, and vertiport-pair choices under budget and capacity constraints. Candidate locations are generated using a Quadtree-based method, and accessibility analysis with geographically weighted regression is used to examine spatial heterogeneity. Based on a case study of travel demand in Guangzhou, the results show that higher elasticity strengthens the model’s market-driven orientation. Vertiport resources shift toward areas with higher housing prices, widening the accessibility gap between areas with high and low housing prices. Sensitivity analysis shows that UAM adoption is more affected by transfer time and the minimum time-saving threshold than by construction budget. Policy experiments indicate that airspace regulation, construction cost subsidies, and service subsidies influence UAM adoption and accessibility through different mechanisms. These findings suggest that UAM planning should jointly consider transfer efficiency, airspace constraints, infrastructure investment, and targeted policy support to balance commercial viability and spatial equity.