The computation is reliant on obtaining hourly directional volume. AADT is first converted to hourly directional volumes, based on the day of week variance factor, hourly factor and directional factor (if directional AADT is not available). Hourly directional volumes used for delay calculation are adjusted for queue spill-back under over-saturation conditions for the time periods between 7:00 a.m. and 10:00 a.m. and between 4:00 p.m. and 7:00 p.m.

Vehicle hours of delay was estimated hourly 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 under uncongested conditions that meet travel times 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 products of additional travel time an average vehicle experienced beyond uncongested conditions and the vehicle volume.

• 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 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.
  • 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.
• Vehicle Hours of Delay: Additional travel time experienced by a motorist beyond what would be experienced under uncongested conditions.
• Vehicular Traffic Volume: The number of vehicles crossing a section of road during a specified time period.