Evaluation of plant selection for traffic calming on residential streets in Tucson, Arizona

Since 1992, Tucson, Arizona has installed seventy-eight traffic circles in residential areas as part of a Neighborhood Traffic Management Program and sixty-seven of these circles contain plants. Plants are included in traffic calming installations because they generally improve visibility and visual quality of these installations. Species selection may directly influence effectiveness of plants in these functions. The intent of this study was to evaluate plant selection in established traffic circles, in Tucson, Arizona to determine their success relating to safety, visual quality and maintenance criteria. The total population was inventoried and each circle was ranked according to how well criteria were met. The results of this study indicate that plant selection met maintenance criteria in most cases but often did not meet criteria for safety and visual quality.