Image maps are graphics that have been designed to be clickable. Selecting different areas of an image map will instruct the browser to load different pages. For example, by clicking on different areas of a map travel information can be obtained for that location.
Image maps should have a text listing of all the options available in the image map. This text listing should be located either above or below the map or on a linked page. It may, in fact, be best to construct a text-only alternate page parallel to the main image mapped page.
There are serious problems for people with visual disabilities.
1. Image map elements are not supported by many text based browsers. Lynx, for instance, does not support the image map element so the information is unavailable.
2. Often the information showing where to click an image map is contained within the image. People using screen readers and other access devices that are designed for graphical user interfaces are presented with problem since what matters is where the image is selected, not simply that it is selected.
3. The image often contains words or graphical instructions within the image that the screen reader does not have access to.
4. The clickable surface must be navigated by a mouse making selections on the basis of what the image looks like.
It is important when designing sites that each hot spot on an image map element should have an alternate text field added. Browsers could be modified to Tab through the image map hot spots reading out the Alternate text and making image maps completely accessible.