At the MBTA, we’re striving to become the global model of accessible public transportation. Our guiding principles of accessibility apply to every part of our system, including trains, stations, and digital signage. Accessible design benefits everyone—seniors, parents, students, commuters, tourists, and countless other customers we serve each day.
There is no single, foolproof checklist to consult when designing accessible content, so we consider the factors that impact a screen, a design, and the individual reading it, including:
Ultimately, the designer is responsible for creating accessible designs and remaining informed of the latest accessibility requirements.
For 30 years, the American with Disabilities Act (ADA) has set the standard for accessible design by ensuring people with disabilities have equitable access to the built environment. And, since 2006, the MBTA/BCIL Settlement Agreement has set the standards for accessibility at the T. As a significant feature of our public transit system, digital signage is designed to meet the requirements set forth both the ADA and the MBTA/BCIL agreement.
This is relatively straightforward, though the real-world application of these mandates on digital experiences is not always as clearly defined. More specifically, the ADA does not set standards for public information on screens.
Section 703.5 of the ADA Standards defines rules for visual characters on signs, which we’ve adopted for our screens (digital signage). Both screen size and viewing distance can impact ADA-compliant types sizes. The most relevant guidelines for minimum accessible font sizes:
703.5.5 Character Height Viewing distance shall be measured as the horizontal distance between the character and an obstruction preventing further approach towards the sign. Character height shall be based on the uppercase letter ‘I’.
Calculated based on specific screen hardware resolution and ADA Standards, 703.5. Examples shown represent typical viewing scenarios, but additional sizes can be calculated by adding 1/8″ of text height per foot of viewing distance.