The vehicle hours of delay are estimated for each hour of the day by determining the difference between actual travel time and the delay threshold travel time along a facility. Delay threshold travel time is the travel time for a motorist during uncongested conditions at the uncongested speed thresholds. The actual travel time is computed based on average travel speeds on a single segment for a single hour. At an areawide level, total vehicle hours of delay are the sum of all segment vehicle hours of delay that are computed by multiplying the single-vehicle hours of delay with the vehicle volume in that segment.

• 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.
• 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 the methodology report.
• Facility Type
  • Arterials: Signalized roadways that primarily serve through traffic, with intersections spaced two miles or less apart.
  • Highways: High-speed roadways with signalized intersections spaced more than two miles apart.
  • Freeways: Multilane, divided highways 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. Multiple highway systems exist in Florida, with the following three maintained by the State of Florida with a little distinction:
  • National Highway System (NHS): Roads designated by Congress as nationally important for inter-regional travel, including roads designated as connectors to NHS intermodal facilities, which are part of the State Highway System, and other NHS 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): A statewide network of high-priority transportation facilities, including the state's largest and most significant airports, spaceports, deepwater seaports, freight rail terminals, passenger rail and intercity bus terminals, rail corridors, waterways, and highways. The FDOT Source Book reports roadway SIS facilities on the SHS or the NHS.
• 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 the AM peak.
  • Daily: For the average 24-hour day.
  • Yearly: Includes all the calendar days in a year, excluding State of Florida holidays and weekends.
• Segment: A portion of roadway defined by two boundary points.
• Traffic Volume: The number of vehicles crossing a section of road during a specified time period.
• Vehicle Hours of Delay: Additional travel time experienced by a motorist beyond the expected travel time in uncongested conditions.