congestiepercentages

Congestiepercentages are a statistical measure used in transport planning to express how much of a given road network experiences congestion during a specified period. They are typically expressed as a percentage and can refer to time, distance, or network presence of congestion.

There are two common interpretations. A time-based congestion percentage represents the share of monitoring time during which a link, corridor, or network is congested, according to a defined criterion such as a minimum travel time increase or a speed threshold. A distance-based version measures the share of road length that is congested at a given moment or over a period. For example, if a link is congested for 30 minutes within a 2-hour observation window, its time-based congestion percentage is 25%.

Data for congestiepercentages come from various sources, including traffic sensors, loop detectors, GPS-based probes, and travel-time databases. Congestion status is usually determined by criteria like average speed, travel-time ratio to free-flow conditions, or occupancy levels. Results can be aggregated at the level of individual road links, corridors, or entire networks.

Applications of congestiepercentages include monitoring traffic performance, evaluating the impact of policy measures or infrastructure projects, and communicating congestion levels to the public. They support planning decisions, prioritization of investments, and regional transport benchmarking.

Limitations arise from differences in definitions and thresholds for what counts as congested, as well as temporal and spatial resolution. Comparability between regions or systems requires standardized methods and clear documentation of the criteria used.