Travel time calculation method for expressway using toll collection system data

Travel time information is important for traffic control systems. If a toll collection system is adopted, we can calculate travel-time from toll collection system data. Little attention has been given to this because of the following problems. Unusual-data (data deviating from the main distribution of travel time data) removal is difficult. When there is only a small number of data, it is difficult to calculate an appropriate travel time. Japanese expressways have service areas and rest areas. Thus, data for vehicles which have stopped for a long time in a service area or rest area are considered unusual data. Data for extremely short travel times, such as by motorbikes, are also considered to be unusual data. It is important to remove these unusual data. Therefore, this research proposes a method of calculating travel time information using data obtained from toll collection systems.