Transportation-disadvantaged (TD) populations, including many older adults and people with disabilities, often face mobility barriers linked to fragmented transportation services, limited information about available ride options, and weak coordination across providers. While One-Call/One-Click (1C1C) systems have emerged as solutions to centralize transportation information, support trip planning, and coordinate services across public, nonprofit, and private actors, their capacity to scale remains limited. Using a mixed-methods design, this study examined the institutional arrangements, functional scope, and service scale of 67 operational 1C1C systems to identify systemic barriers to expanding coordinated service access. Quantitative analysis revealed substantial variation in governance, service configurations, costs, and coverage relative to conservative population-based benchmarks, with most systems operating at limited scale. Qualitative interviews with system administrators provide explanatory insight into these patterns, identifying three recurring institutional constraints: funding instability, limited capacity for technology and data integration, and shallow vendor networks for specialized transportation services. The findings indicate that limits to 1C1C performance are rooted in institutional and financial conditions rather than system design. Situating coordinated transportation within the Age-Friendly Cities framework, the study argues that mobility coordination must be treated as durable public infrastructure if equitable, age-friendly mobility is to be achieved at scale.
Balachandran et al. (Fri,) studied this question.