Inclusive accessibility: Analyzing socio-economic disparities in perceived accessibility

New paper!  Kar, A., Xiao, N., Miller, H.J. and Le, H.T.K. “Inclusive accessibility: Analyzing socio-economic disparities in perceived accessibility,” Computers, Environment and Urban Systems,  114, 102202

Highlights

  • Inclusive access considers both physical and perceptual barriers to travel.
  • Perceptions of safety and comfort vary with people’s socio-economic statuses.
  • Existing infrastructure and services yield unequal access across communities.
  • High-income white populations experience transportation privileges over others.
  • Low-income communities with greater risk exposures perceive higher mobility barriers.

Abstract

Existing accessibility measures mainly focus on the physical limitations of travel and ignore travelers’ perceptions, behavior, and socio-economic differences. By integrating approaches in time geography and travel behavior, this study introduces a bottom-up inclusive accessibility concept that aggregates individual-level travel perceptions across socio-economic groups to evaluate their multimodal access to opportunities. We classify accessibility constraints into hard constraints (physical space-time limitations to travel) and soft constraints (perceptual factors influencing travel, such as safety perceptions, comfort, and willingness to travel). We categorize travelers into 12 mutually exclusive socio-economic groups from a mobility survey dataset of 477 travelers. We apply a support vector regressor-based ensemble algorithm to estimate network-level walking perception scores as soft constraints for each social group. We derive group-specific inclusive accessibility measures that consider space-time limitations from transit and sidewalk networks as hard constraints and minimize the group-specific soft constraint to a certain threshold. Finally, we demonstrate the effectiveness of group-specific inclusive accessibility by comparing it with the classic access measure. Our study provides scientific evidence on how people of varying socio-economic statuses perceive the same travel environment differently. We find that socio-economically disadvantaged communities experience higher mobility barriers and lower accessibility while walking and using transit in Columbus, OH. Our study demonstrates a transition from person- to place-based accessibility measures by sequentially quantifying mobility perceptions for individual travelers and aggregating them by social groups for a large geographic scale, making this approach suitable for equity-oriented need-specific transportation planning.

 

Journal of Geographical Systems 2023 Best Paper Award

Totally chuffed that our paper on “realizable accessibility” has been selected by the Journal of Geographical Systems for the 2023 JGS Best Paper Award:

Inclusive accessibility: Integrating heterogeneous user mobility perceptions into space-time prisms,

New paper: Kar, A., Le, H.T.K. and Miller, H.J. (2023) “Inclusive accessibility: Integrating heterogeneous user mobility perceptions into space-time prismsAnnals of the American Association of Geographers, online first.

Abstract. Travelers’ day-to-day mobility depends on their perceptions, experiences, and personal characteristics. Many accessibility measures overlook perceptual factors and mainly consider space–time limitations of mobility, overestimating travelers’ potential mobility. We introduce a novel inclusive accessibility concept that advances time-geographic accessibility measures in light of travel behavior theories. We conceptualize inclusive accessibility as a subset of the classic space–time prism (STP) that incorporates hard constraints (e.g., limited infrastructure and services and time) and soft constraints (e.g., perceptions of safety and comfort toward the built environment and infrastructure and travel time preferences). We collected survey data on individual-level mobility perceptions and applied machine learning algorithms to predict personalized soft constraints for walking. Considering public transit and walking, we model and compare three network-based STPs: classic STP with hard constraints, inclusive STP with soft spatial constraints, and inclusive STP with soft spatial and temporal constraints. Our method demonstrates heterogeneities in individuals’ mobility perceptions. We illustrate that the individual’s level of accessibility shrinks substantially as we approach more conservative measures that include travel perceptions. Our method highlights the differences between travelers’ physically and psychologically accessible space depending on their travel choices and exposure.