Highway and road signs are getting easier to see, gradually. The U.S. Department of Transportation has directed state and local governments to install replacements made with a fluorescent, reflective material that is more visible. Road safety concerns and an increasing number of aging drivers led to the order. The Tennessee Department of Transportation's assistant chief of engineer operation, Steve Hall, told The Tennessean that the project has really just started. Some municipalities have already started installing the newer signs. Signs that do not meet new standards must be replaced by 2015 and 2018, depending on the sign type. The total cost has yet to be tallied. On older signs, the sheeting that covers an aluminum back runs $1.11 per square foot. The new, more reflective sheeting is $4.70 per square foot.