Level Of Service Timeline Definition

A Level Of Service (LOS) is a measure of the quality of service provided by a transportation system. The LOS is based on the amount of time it takes to complete a given trip, the average speed of travel, and the number of delays experienced along the way.

The LOS is generally expressed as a letter grade, with ‘A’ being the highest level of service and ‘F’ being the lowest. The specific criteria used to determine the LOS may vary depending on the type of transportation system being considered. For example, LOS criteria for freeway systems are different from those used for public transit systems.

The LOS can be used to compare different transportation options, to assess the impact of proposed changes to a system, or simply to track trends over time.