Transportation Level of Service (LOS) is a measure of traffic delay at signalized street intersections or roadway segments (i.e., traffic congestion). Level of Service uses a letter-grade system ranging from LOS A to LOS F. LOS A indicates free flow conditions with little or no delay. LOS F indicates oversaturated conditions with excessive delays. LOS analysis measures the amount of vehicle traffic a project will generate at signalized intersections, then seeks to accommodate the additional traffic either by improving or expanding existing intersections. As such, LOS supports and prioritizes automobile travel over other modes of travel (e.g., walking, biking, transit, etc.).