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.

 

Evaluating accessibility benefits and ridership of bike-transit integration through a social equity lens

New paper. Liu, L., Lee, J. and Miller, H.J. (2024) “Evaluating accessibility benefits and ridership of bike-transit integration through a social equity lens,” Computers, Environment and Urban Systems, 112, 102150.

Abstract. Integration of bike usage and transit services is an effective way to enhance accessibility for both transportation modes. Using high-resolution transit data, the study analyzes bike-transit multimodal accessibility and usage patterns through a social equity lens. Two types of accessibility increment are studied: bicycle increment to public transit – the benefits of using bicycle for transit riders, and transit increment to cycling – the merits of using transit for cyclists. Results show that bike-transit integration benefits both public transit riders and cyclists, expanding their accessible opportunities by up to 70% and enabling longer trips for cyclists while providing continuous benefits for public transit users. Meanwhile, better infrastructure significantly improves multimodal accessibility, resulting in more increment for public transit riders but less increment for cyclists. The paper also shows the spatiotemporal patterns of multimodal ridership. The research highlights disparities in bike-transit activities for Black communities due to inadequate local biking infrastructure. Black people majority neighborhoods enjoy less increment compared to other neighborhoods for shorter and very long trips; they also have disproportionately lower multimodal ridership despite much higher transit ridership and better transit access. Enhancing biking infrastructure in these areas can improve physical accessibility increment and promote social equity. The paper provides practical insights for transit planning, emphasizing the importance of connecting bike lanes and creating safer streets for cycling.

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: