Creating an Accessible Map
One of the things that bothers me about Section 508 is the idea that the only thing needed for an image in an accessible document is that it needs alternate text.
Most images used with a design are there to create some sense of visual story telling; to spice up the content you are looking at. For government documents that end up becoming PDFs, this means making a really boring document look somewhat more appealing when you are reading them. Even pie charts, graphs and diagrams end up with an alt tag describing what the figure is (“This chart shows the decline of funding to blah blah yakkity yak). What got me wondering a while ago was, what about the documents where the image is the most important subject in the document. More specifically, what about maps?
While the majority of maps out there are a little too detailed for PDF purposes to be made Section 508 compliant, there are a lot of other types of maps that should benefit the user, such as Public Transportation maps. Theoretically, with current Section 508 standards, one need only put an alt tag in there. In theory, when reading an accessible PDF, it would have some descriptive text talking about how much it costs to ride the train, and how your city has a bunch of options for moving people, then you have this big ol’ map and all a visually impaired person hears from the screen reader is “Map of our rather complex and unfriendly subway station.” Talk about frustrating.
I wanted to see which cities were tackling this problem, first because I didn’t want to reinvent the wheel, and secondly because I wanted to find ideas for creating a more accessible map. Naturally, after visiting both Massachusetts Bay Transit Authority (MBTA) and New York’s Metropolitan Transit Authority (MTA) websites, neither of them seem to be doing anything to make the bulk of their PDFs 508 compliant. After having lived in Boston, but not in New York, I was intimately familiar with using the MBTA to get around. I figured that subway was probably a safe example to use to try to create an accessible map.
Subway maps have a few issues with accessibility:
- Train Lines go from point A to point Z, then back again.
- Some stops connect to other train lines, buses, and various other transit routes.
- Not all stops are accessible to individuals requiring mobility assistance.
- Routes often split off from each other even though they are on the same line.
- Most are color coded
The source map (PDF) I used from the MBTA has all of the T lines (The MBTA train is called, simply, the ‘T’) on it, showing the relation between each line as well as hosting the route overlaying a grayed out city. Looking closer, not all the stops are listed on the map, making it difficult to determine exactly where to go. After staring at the map for a while, I figured the text was too small to put all the stops on the map and still use all the other routes. Additionally, since the majority of the T is underground, I figured it would be irrelevant to show roughly where the lines fall in the city. In the end I decided to focus on the oldest section of the T, the Green Line. Then I noticed that the stops are essentially a list.
The problem is, which direction do I use to make it useful?
I decided to create a route list going outbound, as the lines originate from one stop (Lechmere) before branching out at Copley and Kenmore.
The way lists are set up in PDF tags makes use of several awesome additional tags that are generally unusable in other tags. If you use alternate text for tags that don’t require it, the document won’t check out okay for Section 508 compliance. The correct structure of a list looks like the following:
<L> <Caption> (Optional) <LI> <Lbl> (Optional) <LBody>
I was able to identify the L tags as Main Green Line, E Line, B Line, C Line and D line and nest the lists like above so I can show routes moving away from the main line. The Caption became useful to designate the individual Lines, and the Lbl tag, which is used to describe the bullet character, was used to identify whether or not the stop was a basic transit stop, a transfer station, or a terminal stop.
I’m not sure if a screen reader like JAWS or WindowEyes can tell the difference between nested lists in tags, so I include directives in the Title field of the Tag Properties Dialog box for certain stops, such as Transfer stations. I’m also not sure what to do about the fact that you can take a train Inbound in addition to leaving outbound from Riverside. Therefore, in the meantime, I numbered the stops along the Main Line, and each of the corresponding stops in the Title section of the LBody tag.
I’m interested to hear any ideas on how to improve this map. If you or someone you know uses a screen reader, please feel free to post your comments to me after checking this file out to give me any feedback about this project. Also, any ideas to improve this would be helpful.