WisDOT travel time information is calculated based on speed data collected by a variety of traffic data detection devices located along a road corridor that is then integrated into the Advanced Traffic Management System (ATMS) software used by the TMC. Received data is calculated to travel times and then communicated to the public using various integrated communication methods, such as 511 Wisconsin and dynamic message signs (DMS).
The minimum accuracy and maximum latency of travel times calculated and disseminated by WisDOT is governed by United States Department of Transportation Federal Rules and Regulations. WisDOT is required to provide traveler information that is accurate per Title 23 CFR Part 511 which mandates travel time accuracy to within 85 percent of the actual travel time delivered to the traveling public within ten minutes of the initial speed measurement with an overall travel time availability of 90 percent. Ensuring that the displayed travel times are accurate provides motorists with confidence that the information provided is indeed accurate and reliable. Travel time information can also be used to assess the overall performance of the transportation network. The department is constantly performing travel time verification, both in the field and by comparison with other available data sources, to perform quality control and quality assurance checks on this critical traveler information data.