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Accessibility of Web Content: Section 508 of the Rehabilitation Act of 1973, as amended (29 U.S.C. 794d), sets the federal standard and the Oklahoma Electronic Information Technology Accessibility (EITA) Act further apply to web postings from Oklahoma Colleges and Universities.  The Oklahoma Electronic and Information Technology Accessibility Act (EITA) statute, effective 2005, applies to all documents managed by an Oklahoma institution.

Preparers of reports to the Oklahoma Department of Transportation which are to be posted to the internet, e.g., SP&R Final Reports, are responsible by contract to prepare the reports to meet the requirements of the above cited statutes as originally prepared as well as amended. This page shares information to assist authors; however, the shared information, while offered in good faith, is the responsibility of the report contractor to be aware of how to prepare an accessible document.

Accessibility Standards

Text Equivalents (alt text)

Text equivalents for visual elements present some unique challenges. This section begins with a philosophical big picture look and works down to the critical needs.

When an author uses a visual element (chart, graph, picture or other),  typically it is included to convey meaning to the reader. That meaning is contextual, so the same visual element may not convey the same meaning all the time. For example: using a picture of a bird in an article about state birds. The alt text equivalent that says “The Scissortail Flycatcher, state bird of Oklahoma” might be most appropriate. However,  if the same picture is in an article about how the bird uses its tail feathers to move more quickly when it hunts, then the text equivalent will be much different.

How does an author determine the meaning the visual element conveys? One technique is for the author to pretend to read the report element to someone over the telephone. This description of the visual element would be in the context of the report element. That statement becomes the text equivalent.

Now that the text equivalent has been created, it is a matter of putting it in the best place. There are three options:

  • Place it in the Alternative Text (alt text) attribute for the element
  • Place it in the caption for the element
  • Place it in the body of the document, adjacent to the element

If the text equivalent is short, say 2-4 brief sentences, then it is reasonable to put it into the element Alternative Text attribute or into the element’s caption. If you put it into the caption, then do not repeat it in the Alternative Text attribute. If you repeat the text equivalent in the visual element’s Alternative Text attribute and its caption, then you force someone using a Braille reader or screen reading software to read that text equivalent twice.

However, leaving the Alternative Text attribute blank can confuse readers. Instead, put something brief in the Alternative Text attribute that ties it to the caption. Even the Figure number from the caption will suffice to do this. Then a brief statement such as “described in caption”.

If the text equivalent is longer than a few short sentences, then it is more appropriate to put it into the caption or into the body of the document, adjacent to the visual element. Captions are not typically more than a few sentences either, but you can create captions that are longer than what Alternative Text attributes should be.

Long descriptions are often necessary if the visual element is a chart or graph with many data points. A longer description may also be necessary if the visual element is an image that has details that are important. If the description is longer, then put it into the body of the document itself. Place it immediately before or after the visual element that is described. Then, use the Alternative Text attribute to tell the reader where the text equivalent is located. If a paragraph that describes the visual element is immediately after the element, then the Alternative Text attribute could say “Longer description follows in the next paragraph”.

Much more information about text equivalents is available from The DIAGRAM Center


  • Text equivalents convey the meaning of an image. Write a text equivalent as if is being read to someone over the telephone.
  • Put the text equivalent into the Alternative Text attribute if it is 2-4 short sentences or less.
  • Put the text equivalent into the figure caption if it is longer than 2-4 short sentences, but not long enough to be a paragraph.
  • The Alternative Text attribute should reference the caption as the source for the text equivalent: “Description follows in caption,” for example.
  • Put text equivalents that are too long for captions into the body of the report, immediately adjacent to the figure.
  • The Alternative Text attribute should reference the description in the body of the document: “Description in report immediately before/after figure”, for example.
  • Captions often provide information about the figure but do not convey its intended meaning. For example, if the image shows a device, then the caption might say “A custom-made device that performs soil measurements”. This information probably does not serve as a text equivalent for the image.
  • The text equivalent in the Alternative Text attribute might describe the important features of the device’s appearance, if that is the intended meaning of the figure.

Learning Opportunities

The Oklahoma Transportation Library (OTL) offers opportunities to assist authors as well as references to related materials.

Common report authoring software such as Microsoft WordTM  and Adobe AcrobatTM offer tools to assist with preparing accessible documents; however, both programs have disclaimers with respect to the details of meeting accessible document needs. Specific examples include color contrast testing, table structure, and the suitability of author prepared Alternative Text.

The OTL has presented two workshops to assist authors with preparing Microsoft WordTM  documents. Since the WordTM document is a precursor to the AcrobatTM version, the quality is directly reflected by the quality of the WordTM document.

The April 2016 workshop OTL Enhancing Microsoft Word Accessibility Skills April 2016 covered common WordTM skills that technical writers use. The closed captioned workshop is available at and the slides as well as the transcript are posted at .                              

The November 2016 workshop OTL Advanced Accessibility webinar provides additional detailing for contrast checking and table structure as well as additional topics. The workshop was presented in an interactive format and the starting files for the Accessible Tables creation part of the workshop are available at    The color contrast notes and the text equivalent (alt text) notes are on this page. The video workshop is available at without closed captioning. The workshop closed captioned version and the transcript will be made available here when it is available.

To aid the preparation of accessible documents the US Veterans  Administration provides many tutorials that are available at

the  AcrobatTM tutorials are available at


the WordTM tutorials are available at .

Using Color or Shading an a Document

Color Contrast

Color is often used in reports, e.g., to emphasize textual elements or to distinguish  lines in graphs and charts. Unfortunately, such designations are often unreadable to color blind readers. The US National Institutes of Health  ( ) shares " as many as 8 percent of men and 0.5 percent of women with Northern European ancestry have the common form of red-green color blindness." Distinguishing shades between closely related colors, color contrast, is difficult for many viewers.  The color contrast ratio of 4.5:1 posted by the Web Accessibility Initiative (WAI) is a commonly used criterion. A common tool for testing contrast is the Colour Contrast Analyser: .

The box below shows the importance of color contrast checking. The text towards the left is readable; however, as as the reader progresses to the right, the background is not suitable for reading. This topic is discussed in the November 2016 workshop presentation. By using the Colour Contrast Analyser the author of the text bos would have been able to determine the maximum amount of background shading that would be acceptable. 

The other great concern in reports is the use of color to convey information. It is in generally fine to use color to convey meaning as long as you use another visible cue in addition to color.

  • Graph and charts lines or elements in a bar graph can have visual elements such as high contrast symbols (open triangles, closed circles, squares, etc.) added to lines. In a bar graph, high contrast cross hatching and other symbols are readily available. Symbols or Cross hatching in the same color as the bar or line is not helpful.
  • It does not help to add additional information about visible elements in alternative text Description. This information is hidden and only available to people using screen reader/braille display technology.

Image Editing

Another approach to modifying graphs and charts is to use an image editor. Add a text label to an image in an image editor, then insert a new image into document. However, be aware of color contrast when you add text to a background: The chart or graph creation is dependent upon the software used to create the object. However, the listing below shows a pattern common to many versions of popular software.

Using Microsoft Excel:

Bar chart

  • Insert chart as usual
  • Click on chart area
  • Click on Plus sign at top right
  • Check Data Labels
  • Select label
  • Select Label Options at far right
  • Check additional items, mainly, Series Name

Line graph

  • To just add one label to a line, select one data point on a line
  • Select Plus sign
  • Select Data Labels
  • Select Label Options at far right
  • Select label
  • Check Series Name, uncheck Value

Add markers to line graph

  • Select series
  • Select Fill and Line (paint can)
  • Select Markers
  • Expand Marker Options
  • Specify shapes, size, etc.

When complete save the object as an image in 2013 or 2016 Excel ( .

The images created above, or any image, may be updated for accessibility using an image editor.  This technique may also be used when images are created in software that does not allow line, editing or when the image is copied from a document  An excellent free and open source editor is the GIMP image editor:   [the acronym GIMP - GNU Image Manipulation Program, where GNU, pronounced as for the animal (n(y)o͞o/) comes from the GNU operating system].