The combination truck average speed for an area is calculated by summing the products of the segment average speeds and the segment combination truck miles traveled (CTMT) and then dividing it by the total segment CTMT.

• 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 Average Speed: The average speed at which combination trucks travel a section of the roadway during a specific time period.
• Combination Truck Factor: The proportion of heavy vehicles that are combination trucks (FHWA Vehicle Classes 8-13) to all vehicles.
• Combination Truck Miles Traveled (CTMT): Estimated amount of travel for combination trucks in a geographic region over a period of time. It is calculated as the sum of the number of miles traveled by each combination truck.
• 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
  • 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 in the AM peak.
• Segment: A portion of roadway defined by two boundary points.