It is important to make sure that your documents are accessible to as many people as possible. For FHWA and other publications funded through the U.S.Government, Section 508 compliance is required. In addition, there are an increasing number of lawsuits being filed against entities that post documents that are not accessible.

For tutorials, checklists, and guidelines, see



Make sure that graphs and other images do not rely solely on color to convey information. If necessary, use online tools such as Coblis or Sim Daltonism to test your images.

Bar Charts

Even if you are color coding, make sure values or labels are included with each bar for screen readers. If the color differences are significant to understanding the chart, make sure that they have sufficient color contrast and difference in darkness for a colorblind user to interpret.

Example 1. The below bar chart includes labels on each bar. Color contrast needs to be checked to make sure that there is enough contrast between the white text (foreground) and the red, orange, blue, and gray bars (background). In addition, if the bar colors are significant and correspond with a key, then the contrast between each bar color also needs to be checked.