Each year, the Washtenaw County Road Commission takes hundreds of traffic counts on county roads. Traffic counts assist the Road Commission in monitoring the county road system and are useful in many engineering applications.
Typical traffic counts are taken over a 24-hour period and take into account both directions of travel.
By monitoring the county road system, the Road Commission is better able to determine areas of growth and plan transportation projects that best serve the motoring public. In addition, traffic counts are an essential element of many design projects and traffic engineering studies such as those for determining traffic signals and multi-way stops.
Traffic counts are taken by placing a pair of rubber hoses across the road. These hoses send air pulses to an automatic traffic recorder when a vehicle crosses each hose. Some traffic counts also break down the vehicle classification (such as commercial vehicles) and measure the speed of vehicles.
The Washtenaw County Road Commission stores all available traffic counts in an online database through a partnership with the Southeast Michigan Council of Governments. The database is open to the public and can be searched by township, road name or volume. Questions about how to use the database can be answered by clicking on the Help Icon at the top of the database web page.
The Road Commission Office is located at 555 N. Zeeb Road, Ann Arbor, MI