The combination truck hours of delay are 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 combination truck under mildly or heavily congested conditions. The actual travel time is computed based on average travel speeds on a single segment for a single hour. At an areawide level, combination trucks hours of delay are the sum of all segment combination truck hours of delay.

• Area Type
  • Urban Area: An area with at least 2,000 housing units or at least 5,000 people.
  • Rural Area: An area with less than 2,000 housing units or less than 5,000 people.
• Combination Trucks: Vehicles classified as Classes 8-13 by Federal Highway Administration; commonly referred to as a “semi-truck”.
• Combination Truck Factor: The proportion of heavy vehicles that are combination trucks (FHWA Vehicle Classes 8-13) to all vehicles.
• Combination Truck Hours of Delay: Additional travel time experienced by a combination truck beyond the expected travel time in uncongested conditions.
• Combination Truck Volume: The number of combination trucks crossing a section of a roadway during a specified 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 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 Period
  • Daily: For the average 24-hour day.
• 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.