Texas Driver Understanding of Abbreviations for Changeable Message Signs

Abstract

Research was conducted as part of an ongoing project for the Texas Department of Transportation to evaluate the use of changeable message signs (CMSs) in Texas. The objective was to determine motorist understanding of abbreviations for use on CMSs. A human factors study was conducted in six locations in Texas. Participants were given a list of abbreviations and were asked to interpret the full words or phrases. The results identified 24 abbreviations that were understood at an acceptable level for use on CMSs in Texas; acceptability was based on a criterion of 85 percent or more of the participants’ correctly interpreting the word or phrase. Differences in study location comprehension levels were also examined. Twelve abbreviations were recommended for use only at particular locations on the basis of the varying comprehension levels among the six study locations. Abbreviations that were understood by less than 85 percent of the participants were not recommended for use in Texas.