The average travel speed for each segment is derived by summing the percent of volume at heavily congested (HC) speeds multiplied by the heavily congested speed, the percent of volume at mildly congested (MC) speeds multiplied by the mildly congested speed, and the percent of volume at uncongested (UC) speeds multiplied by the uncongested speed. The average travel speed for an area is calculated by summing the products of the segment average speeds and the segment VMTs and then dividing it by the total segment VMT. Field-measured travel speed data, provided by HERE Technologies through Regional Integrated Transportation Information System (RITIS) at the University of Maryland’s (Center for Advanced Transportation Technology) CATT Lab, is used for speed. The field-measured travel speed data covers most of the State Highway System (SHS) and National Highway System (NHS) roadways. On roadways where the speed data does not cover the SHS or NHS, speeds are calculated based from speed volume functions.

• Area Type
  • Urbanized Area: An area with a population of at least 50,000 people.
  • Non-Urbanized Area: An area with a population less than 50,000 people.
• Average Travel Speed: The speed at which motorists travel a section of the roadway during a specific time period.
• Context Classification: A classification assigned to a roadway that broadly identifies the various built environments in Florida, based on existing or future land use characteristics, development patterns, and the roadway connectivity of an area. For more information about context class, please reference methodology document.
• Facility Type
  • Arterials: Signalized roadways that primarily serve through traffic with average signalized intersection spacing of two miles or less.
  • Highways: High speed roadways with signal spacing greater than two miles per signal.
  • Freeway: A multilane, divided highway with at least two lanes for exclusive use of traffic in each direction and full control of ingress and egress.
• Highway System: An integrated network of roads and highways for motor and non-motor transport. Each highway system has roadways that are exclusive to their respective system.
  • National Highway System (NHS): Roads designated by Congress as nationally important for inter-regional travel, including roads designated as connectors to NHS intermodal facilities.
  • State Highway System (SHS): Roads under the jurisdiction of the State of Florida, and maintained by the Florida Department of Transportation or a regional transportation commission; includes roads with Interstate, US, and SR numbers.
  • Strategic Intermodal System (SIS): Transportation system created by the Florida Legislature in 2003 to include statewide and regionally significant facilities and services, containing all forms of transportation for moving both people and goods, including linkages that provide for smooth and efficient transfers between modes and major facilities.
• Reporting Periods
  • Peak Hour: 5:00 p.m. to 6:00 p.m. on a weekday. This hour is chosen to allow consistent comparisons among transportation modes. It may not be the hour of greatest travel for any given roadway, mode or area. The majority of travel typically occurs during the PM peak hour resulting in more congestion in the PM peak than observed in the AM peak.
  • Peak Period: 4:00 p.m. to 6:00 p.m. on a weekday in which travel is greatest. These peak period hours are chosen based on the hours of greatest travel in different area types.
• Segment: A portion of roadway defined by two boundary points.
• Vehicle Miles Traveled (VMT): Estimated amount of travel for all vehicles in a geographic region over a given period of time. It is calculated as the sum of the number of miles traveled by each vehicle.