Accessibility is essential for some, and useful for all. As someone who works on the designs of our products, there are a number of things that we can do, to prevent introducing unnecessary barriers and creating a lessened experience for some of our passengers.
Perceivable
Colour contrast
Many people have colour vision deficiencies. It is estimated that 1 in 12 men have the most common form of colour blindness, which means that some people find it easier to perceive content when the foreground and background colours have enough contrast.
The Web Content Accessibility Guidelines set out some technical requirements to meet, to pass AA requirements.
- Regular text should have a minimum contrast of 4.5:1
- Large text (24px, or 19px and bold, or larger) should have a minimum contrast of 3:1
- UI components should have a minimum contrast of 3:1
Our themes contain guidance on which colour combinations may be used, and for what purpose.
Don’t rely on colour alone
People, including those with colour vision deficiencies, and low vision, may not easily perceive or understand content when colour is the only means of communication. Including additional cues, such as underlines, shape, iconography/text and patterns will include more people in this content.
Provide alternatives
Digital products are made up of text and multimedia. To include as many people as possible we need to consider their needs.
- A visually impaired screen reader user will need alternative text for informative, functional and emotionally rich images.
- A deaf, or hard-of-hearing, visitor will need captions for our video, or audio, content.
- Some content may also present barriers to people with cognitive impairments, consider other means to achieve the same goal.
- Some people with motor impairments may need to view content in a particular orientation, so our mobile apps could be presented in a way that considers more visitors’ needs.
Operable
Focus order
Some people, including people with mobility impairments, will use their keyboard to navigate sequentially through content on a page. Creating a logical tab order allows people to move through all of the interactive elements easily. This is usually from left to right and top to bottom.
Interacting with content
To create as pleasurable experience as possible, interactive elements should include considerations for people with mobility impairments; someone with limited dexterity, including some of our older passengers, may benefit from the following.
- Touch target sizes should meet, or ideally exceed, 24 x 24px on the web.
- For mobile apps, consider Android and iOS’ recommendations for touch target sizes.
- Maps, carousels, and other complex patterns should provide ways for people to get to the content without needing to perform a complex gesture, such as dragging, clicking and holding, or pinching.
Understandable
Clarity
A page, or view, should be structured in a way that is clear and consistent. Content should be surrounded with ample white space, and organised in a logical and predictable manner.
The size of heading levels can help people to associate content and to give an idea of the relative importance. For visually impaired screen reader users, the coded heading levels should also communicate this in a non-visual way.
Content design
Written content should be presented in plain language to include as many people as possible, including people with low literacy, or people viewing content in an alternative language.
To include visually impaired screen reader users, we should aim to avoid content, such as “Read more”, and instead highlight what content you will be reading more about.