The person miles traveled (PMT) is computed by multiplying vehicle miles traveled (VMT) by the average vehicle occupancy. Average vehicle occupancies were calculated for each county using the methodology from FDOT’s Vehicle Occupancy Factor and Transit Occupancy Factor Calculation (VOF)with data from the Crash Analysis Reporting System.

• Annual Average Daily Traffic (AADT): The total volume of traffic on a roadway segment over one year, divided by the number of days in the year.
• 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.
• Average Vehicle Occupancy: The average number of occupants in a vehicle. Average vehicle occupancies were calculated for each county using data from the Crash Analysis Reporting System. Details can be found in the full VOF report.
• 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 (with Interstate, US, and SR numbers) under the jurisdiction of the State of Florida and maintained by the Florida Department of Transportation or a regional transportation commission.
  • 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.
• Person Miles Traveled (PMT): Estimated miles traveled by all motor vehicle occupants in a geographic region. It is computed by multiplying vehicle miles traveled (VMT) by the average vehicle occupancy. For the purpose of the Source Book, only trips in motor vehicles are counted.
• 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.
• 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 Miles Traveled (VMT): Estimated amount of travel for all vehicles in a geographic region over a period of time. It is calculated as the sum of the number of miles traveled by each vehicle.