My next post for GovHack is accessible maps.
Now at a later date, have a look at OzWiki: Interactive Maps factsheets. But for now, I know you’re all busy, so I’ll summarise it for you. The important things you need to do to make a map accessible is:
- Providing a long description of the map in text or HTML.
- Providing an ALT attribute for image-based maps.
- Ensure client-side image maps have accurate ALT attributes to indicate areas of a map or important markers
- Making the map keyboard accessible.
- Making an HTML version of any JavaScript features of the map.
- Using only high contrast colours (see my post on colour contrast)
- Not relying on colour to differentiate important parts of the map.
- Ensure that your maps use:
- borders to separate one area from another;
- different types of shading and change of colour to indicate different areas.
- label markers with an ASCII character and individual colours for different markers.
- Allowing users to increase the size of the map, legend and any text.
- Often maps do not respond to browser requests to increase size, therefore additional methods may be required to:
- provide a “large” version of the map, where the user has increased the normal text size by 200%; and
- maximise a particular point/area, or add a highlight box that shows the particular point/area in a larger size.
Code snippets
Want to know how to do the above – check out the OzWiki Developer factsheet on Interactive maps.