The Department of Transportation in each state is responsible for the improvements and repairs of that state’s roads. One important job is to repaint the road lines that have worn away or faded. A painting crew is painting a 24-mile stretch of road. They have already completed a total of 9.5 miles of the road. The crew has been painting at a rate of 0.25 mile per hour and continues to paint at the same rate. What is the unit rate of change in this situation?