TRAVEL TIME DISTRIBUTION MODELS FOR TWO-WAY ROADS WITH TWO LANES

Transportation planners and traffic engineers rely heavily on traffic data in planning projects, construction, operations, and management. In particular, travel time-related data are used to evaluate both the effectiveness and the result of various transportation strategies. Such emerging technologies as AVI and GPS hold great potential for identifying network travel times, but the high cost of initiation of new technology remains a well known problem. Travel time distribution models for two-way roads with 2 lanes are proposed, considering fluctuations of traffic flow. A fundamental distribution of travel time on each level of volume is derived by the use of the relationship between travel time and speed, which is represented by a normal distribution for noncongested flow and a log-normal distribution for congested flow. Based on the traffic volume distribution and fundamental distribution of travel time, the distribution model of travel time for actual traffic flow is also obtained, and some characteristics of travel time distribution.