The concept of measuring traffic congestion has evolved over the past several decades. At the same time, congestion has "evolved" from a condition afflicting only central cities to a pervasive metropolitan problem. NCHRP Project 7-13, Quantifying Congestion, was assigned the task of developing methods to measure congestion on roadway systems. Its goals were to develop methods that are both reliable and understandable; can apply to a route, subarea, corridor, or entire urban region; can relate to simple and easy-to-obtain parameters; and can be forecast. The measures and methods described in this report focus on the needs for congestion and mobility information. This project investigated the range of uses, users, and audiences that are associated with congestion and mobility information to determine which measures would best satisfy the range of needs. The measures and data collection procedures center on the use of travel time-related procedures. There are also methods to adapt existing volume count and capacity estimation procedures to prepare congestion estimates in appropriate formats. (A)
Samenvatting