Duration of Congestion
Updated Using 2022 Data

The duration of congestion is the average length of time during a weekday when roadways subject to congestion operate at heavily congested speeds. Segments are assumed “subject to congestion” when at least 15 minutes of the day have an average speed below the heavily congested thresholds. The average number of minutes heavily congested—weighted by lane-miles—is the area’s duration of congestion. To account for directional travel, the direction of travel with more heavy congestion is chosen for this computation.

Methodology

Methodology: Duration of Congestion

The duration of congestion is the length of time on a roadway of a facility or area type that is categorized as heavily congested. At an areawide level, segments are assumed heavily congested when at least 15-minutes of an hour has an average speed at the heavily congested threshold. The average number of hours heavily congested, weighted by lane-miles, is the area or facility’s duration of congestion. To account for directional travel, the direction of travel with more heavy congestion is chosen for the total duration measure. The congestion thresholds are available here.

Calculation

`"Duration of Congestion" = (∑_("i=1")^("# Segments") "Lane Miles"_(i) × ∑_("j=1")^("24") "Probability Hour is Heavily Congested"_(ij))/(∑_("i=1")^("# Segments") "Lane Miles"_(i))` given that Segment i has at least 15 minutes of heavy congestion

Reporting Periods

  • Peak Hour
  • Peak Period
  • Daily
  • Yearly
Definitions

Definitions: Duration of Congestion

  • 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.
  • Duration of Congestion: The average length of time during a weekday when roadways subject to congestion operate at heavily congested speeds.
  • 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
    • Daily: For the average 24-hour day.
  • Segment: A portion of roadway defined by two boundary points.
Download Data

Date of last refresh: 10/19/2023

SOURCES

FDOT - Traffic Characteristics Inventory
FDOT - Roadway Characteristics Inventory Feature 147 (Strategic Intermodal System)
HERE Technologies - Travel Time Data