Accessibility

Why buses can’t get wheelchair users to most areas of cities

New publication: Liu, L., Kar, A., Tokey, A. Le, H.T.K. and Miller, H.J. (2023) “Disparities in public transit accessibility and usage by people with mobility disabilities: An evaluation using high-resolution transit data,” Journal of Transport Geography, 109, 103589.

Abstract: Many people with mobility disabilities (PwMD) rely on public transit to access crucial resources and maintain social interactions. However, they face higher barriers to accessing and using public transit, leading to disparities between people with and without mobility disabilities. In this paper, we use high-resolution public transit real-time vehicle data, passenger count data, and paratransit usage data from 2018 to 2021 to estimate and compare transit accessibility and usage of people with and without mobility disabilities. We find large disparities in powered and manual wheelchair users’ accessibility relative to people without disabilities. The city center has the highest accessibility and ridership, as well as the highest disparities in accessibility. Our scenario analysis illustrates the impacts of sidewalks on accessibility disparities among the different groups. We also find that PwMD using fixed-route service are more sensitive to weather conditions and tend to ride transit in the middle of the day rather than during peak hours. Further, the spatial pattern of bus stop usage by PwMD is different than people without disabilities, suggesting their destination choices can be driven by access concerns. During the COVID-19 pandemic, accessibility disparities increased in 2020, and PwMD disproportionately avoided public transit during 2020 but used it disproportionately more during 2021 compared to riders without disabilities. This paper is the first to examine PwMD’s transit experience with large high-resolution datasets and holistic analysis incorporating both accessibility and usage. The results fill in these imperative scientific gaps and provide valuable insights for future transit planning.

Media

Neighborhood social determinants of health and postoperative weight loss

New publication – Pratt, K.J., Hanks, A.S., Miller, H.J., Outrich, M., Breslin, L., Blalock, J., Noria, S., Brethauer, S., Needleman, B. and Focht, B. (2022) “The BARI-hoods Project: Neighborhood social determinants of health and postoperative weight loss using integrated EHR, Census, and county data,” Surgery for Obesity and Related Diseases, online first.

(I may be the first geographer to co-author a paper in Surgery for Obesity and Related Diseases, but I am willing to be corrected.)

HIGHLIGHTS

  • While living in close proximity to foods stores does not ensure utilization, in this study, patients who lived within a 10-minute walk to food stores had better weight loss two years after bariatric surgery.
  • Black patients with access to more food stores within a 10-minute walk and White patients with more access within a 5-minute walk had greater %TWL (percent total weight loss)  over 24 months.
  • Living in areas with lower poverty levels did not negatively affect weight loss for Black patients.
  • There were no significant associations for weight loss based on unemployment rate or proximity to fitness/recreational facilities and percent open area.

ABSTRACT
Background.  While social determinants of health (SDoH) have gained attention for their role in weight loss following bariatric surgery; electronic health record (EHR) data provides limited information beyond demographics associated with disparities in weight loss.

Objective. To integrate EHR, Census, and county data to explore disparities in SDoH and weight loss among patients in the largest populous county of Ohio.

Setting. 772 patients (82.1% female; 37.0% Black) who had primary bariatric surgery (48.7% gastric bypass) from 2015-2019 at The Ohio State University.

Methods. EHR variables included race, insurance, procedure, and %TWL at 2/3, 6, 12, and 24 months. Census variables included poverty and unemployment rates. County variables included food stores, fitness/recreational facilities, and open area within a 5- and 10-minute walk from home. Two mixed multilevel models were conducted with %TWL over 24 months, with visits as the between subjects factor; race, Census, county, insurance, and procedure variables were covariates. Two additional sets of models determined within group differences for Black and White patients.

Results. Access to more food stores within a 10-minute walk was associated with greater %TWL over 24 months (p=0.029). Black patients with access to more food stores within a 10-minute (p=0.017) and White patients with more access within a 5-minute walk (p=0.015) had greater %TWL over 24 months. Black patients who lived in areas with higher poverty rates (p=0.036) experienced greater %TWL over 24 months. No significant differences were found for unemployment rate or proximity to fitness/recreational facilities and open area.

Conclusion. Close proximity to food stores is associated with better weight loss two years after bariatric surgery. Lower poverty levels did not negatively affect Black patient weight loss.

Measuring the impacts of dockless micro-mobility services on public transit accessibility

New paper:  Liu, L. and Miller, H.J. (2022) “Measuring the impacts of dockless micro-mobility services on public transit accessibility,” Computers, Environment and Urban Systems, 98, 101885.

We develop new measures of the accessibility increments to public transit afforded by dockless micromobility. We apply this to public transit and Lime scooter data for Columbus.  We find that dockless micro-mobility services such as scooters can improve public transit accessibility, but the benefits are very uneven and face substantial challenges including capacity and cost.

Abstract: Dockless micromobility services have potential as a fast and flexible solution to short-distance trips and public transit’s first-mile/last-mile (FM/LM) access problem; however, these services also have limitations, including uneven spatial distribution, low capacity, and user out of pocket expense. This can impact on the ability of micromobility to enhance public transit accessibility. We introduce accessibility increment measures – the amount by which public transit accessibility improves due to micromobility services. We apply these measures to hypothetical trips using public transit and micromobility data from Columbus, Ohio, USA. We find dockless scooters can increase accessibility by multimodal public transit trips, with increments in the first mile significantly outweighing last mile accessibility increments. Accessibility increments are highly concentrated in the city center due to the distributions of scooters and bus stops. We also find that scooters’ accessibility increment contribution is highly unequal: a small number of scooters contribute most of the accessibility increments. Monetary cost simulations show that the first-mile accessibility increment will rapidly decrease and last-mile increment slightly increase with lower willingness to pay. Capacity simulations show a group of users’ accessibility increment will rapidly decrease as the group size increases, but this depends on whether they are competing or collaborating for scooters. Our results show that despite showing promising potentials, vendors and policymakers still need to address these issues to make collaboration between public transit and dockless micromobility sustainable and equitable. The paper provides measures and evidence for future transit and micromobility planning for scooter vendors and transit authorities.