Usability of Access Ramps and Securement Systems on Transit Buses for Wheeled Mobility Device Users

PURPOSE: People with disabilities often experience decreased community participation due to barriers in transportation and community mobility. Recent studies substantiate ongoing access problems with boarding and disembarking buses experienced by public transit riders with mobility impairments (Frost, Bertocci, & Sison, 2010; Frost, Bertocci, & Smalley, 2015). Among wheeled mobility device (WMD) users living in areas served by public transit, 40% indicated that they had access problems with transit vehicles (LaPlante & Kaye, 2010). In response, manufacturers have been evolving designs to improve usability for WMD users and bus drivers. This study evaluated the usability of six ramp deployment conditions using a state-of-practice electromechanical access ramp and three securement systems encountered by WMD users when riding transit buses. The goal was to assess whether emerging equipment options afford advantages for WMD users over traditional options.

DESIGN: The design was quasi-experimental. Each participant experienced all test conditions. A convenience sample of adult WMD users (N = 36) was recruited from the local community. Three user groups were sought, including those who used power wheelchairs (PWC; n = 15), manual wheelchairs (MWC; n = 15), and scooters (SC; n = 6).

METHOD: The lab apparatus was a full-scale mock-up of a transit bus. Six ramp conditions were assessed, representing a range of real-world bus ramp deployment scenarios. Three WMD securement systems were evaluated: (1) a conventional forward-facing, four-point tie-down system, (2) a forward-facing, three-point tie-down compartment system, and (3) a rear-facing, electromechanical system.

Test conditions were counterbalanced within groups to mitigate order effects. For each condition, participants were instructed to board and exit the bus and participate in the WMD securement process as they would in everyday transit use. Usability was assessed with user-reported ratings of difficulty, acceptability, and safety. An observer measured task time and level of assistance and facilitated open-ended interviews. Descriptive and comparative analysis of usability ratings, performance outcomes, and qualitative data were used to evaluate the data.

RESULTS: PWC users rated the difficulty of all slope conditions as easy but provided neutral ratings of the acceptability and safety (i.e., neither acceptable nor unacceptable and neither safe nor unsafe) of the steepest condition. SC and MWC users provided similar ratings across most conditions. However, MWC users reported the steepest condition as moderately unacceptable and moderately unsafe. Among securement conditions, the majority of study participants preferred the electromechanical rear-facing system, rating it as easier to use, faster to use, and requiring less assistance to use. The qualitative data gathered from the interviews support these findings and give specific examples of usability issues and user recommendations for improving equipment features.

CONCLUSION: Most of the ramp conditions were considered acceptable by participants; however, the two steepest conditions were rated to have greatest difficulty and necessitated assistance for several MWC users. Although some participants preferred the two traditional securement systems, the electromechanical system offers a promising alternative that is faster, reduces driver effort, and decreases the physical invasiveness to WMD users.

IMPACT STATEMENT: These findings will help occupational therapists anticipate potential barriers to public transit that clients may encounter and suggest accommodation strategies to improve community mobility outcomes. The ramp usability data may also ultimately affect federal policy regarding allowable slopes for transit vehicles.

References

Frost, K. L., Bertocci, G., & Sison, S. (2010). Ingress/egress incidents involving wheelchair users in a fixed-route public transit environment. Journal of Public Transportation, 13(4), 41–62.

Frost, K. L., Bertocci, G., & Smalley, C. (2015). Ramp-related incidents involving wheeled mobility device users during transit bus boarding/alighting. Archives of Physical Medicine and Rehabilitation, 96, 928–933. https://doi.org/10.1016/j.apmr.2014.12.013

LaPlante, M. P., & Kaye, H. S. (2010). Demographics and trends in wheeled mobility equipment use and accessibility in the community. Assistive Technology, 22, 3–17. https://doi.org/10.1080/10400430903501413