Frequently Asked Questions: Maps, Geography

We are not aware of any standard operating procedures for making historical maps accessible but there are several aspects to map accessibility which need to be considered:

• Support for individuals with limited vision
• Support for individuals who do not perceive color
• Support for individuals who are blind
• Support for people with cognitive disabilities

Each is discussed a bit below. 

Support for individuals with limited vision

Individuals who have limited vision often need higher contrast and larger print. If you are creating a map or representing it, make sure to keep contrast icons and background and between areas on the map at a 3:1 color contrast ratio or use borders. If you are presenting a historical map with low contrast, treat this support as you would for someone who is blind (notes below).

Support for individuals who do not perceive color

Individuals who do not perceive color need additional indicators such as texture or text to convey information. Whenever the color indicates something, make sure the information is conveyed in an additional way. Meeting contrast requirements (noted above) can be sufficient if the information being conveyed is a boundary or border.  Again, this is not as easy with historical maps but if they are scanned you could consider creating an alternative or overlay with higher contrast and added visual information.

Support for individuals who are blind

How you make a map accessible to people who are blind will depend on the purpose of the map and how the individual viewing it will use it.  In particular, it will depend on whether the map will be used for a purpose known to the map provider or whether the use will be exploratory.  As an example, you can provide a geographical map to provide directions or to allow someone to explore the geography to find the best place to hike.

In the first example, the person presenting the map knows the information (in this case the directions).  Provide a detailed text description alternative to the map in the form of directions. You can see an example of this on the Library floorplan pages.  This detailed text description approach can be used for other purposes. Some maps provide data that can be provided as a CSV file which can be explored so, again, depending on the purpose, that may be an alternative to explore. 

In the second example, providing an alternative is much more difficult. A tactile version is a great alternative. Another is an interactive digital version that allows the user to explore by hovering over or tabbing through content. In this case, you should pay attention to target areas as well as text alternatives.   Both are not simple to create and it may be easiest to provide the service on a “on request” basis.  Tactile maps can often be 3D printed or ordered from services such as Lighthouse for the Blind. 

Support for individuals with cognitive disabilities

Not everyone can read and interpret maps.  Providing a text description of key information and a key that clearly explains textures and icons used throughout the map. When the presenter knows the purpose of the map, then the alternative created for individuals who are blind also will benefit individuals with cognitive disabilities.  Distances may also provide a challenge, so when that is an important piece of information consider providing references the individual would know (such as the length of a football field or the distance between Baltimore and DC if you happen to live in this region). 

Additional resources:

• Making Web Accessible Maps (University of Viriginia) - This resource provides details on some of the topics above.
• Making GIS Data Accessible and ADA Compliant (video) - AT 18:40 mark it includes a great overview of what a detailed text description includes. 
• Ta11y - Charts and Graphs - While not specifically on maps, it provides examples that apply to maps as well.