The Indiana Department of Transportation (INDOT), through its Traffic Monitoring Section, collects, summarizes, and interprets information on the traffic traveling on the state's highway system. The data is used to assess transportation needs, system performance and to develop highway planning and programming recommendations. Traffic data also plays a very important role in route planning and in the design of highway projects.

To collect this information, the Department operates two traffic-monitoring systems:

1. A Statewide Traffic Monitoring System consisting of 110 permanent continuous count stations that collect volume, speed, and vehicle classification data 24 hours per day, 365 days per year. Fifty of these sites also utilize weigh-in motion (WIM) technology to collect continuous truck weight data. These sites are located throughout the state to monitor overall traffic trends. Information from these counters is used to determine ANNUAL TRAFFIC GROWTH trends as well as develop AXLE, WEEKDAY and SEASONAL adjustment factors used with the state’s coverage count program to determine estimates of annual average daily traffic (AADT).

2. The Statewide Coverage Count Program utilizes portable traffic counters to collect 48-hour traffic counts on all State Highway System traffic sections and in rural and small urban areas and all highway performance-monitoring sections (HPMS). The coverage count program operates on a three-year cycle, counting one-third of all sections annually, or approximately 10,000 of the 30,000 count sites. Where possible, portable classifiers are used so that approximately 65% of all coverage counts collected are classification counts. Additional counts are taken within this program to support specific state projects. INDOT is transitioning the coverage count data collection from a central office operation to the six INDOT districts. In addition, INDOT also contracts with three Metropolitan Planning Organizations (MPOs) to collect coverage count data within their areas.

INDOT Average Daily Traffic Volume
Travel Activity by Vehicle Type and Functional System *