The Iowa Department of Transportation's Office of Systems Planning, in cooperation with the Federal Highway Administration, prepares this biennial
traffic report. This report is used by federal, state, and local governmental agencies in determining highway
needs, construction priorities, route location, and environmental impact studies; and the application of
appropriate design standards. The public uses this information in determining the amount of traffic that
passes a given area as they make their development plans and propose land use changes. The above reflects
only a few of the many technical uses for this data.
Starting in the 2010 report, traffic-volume segments include the mainline, ramps, loops, and connections
at interchanges while inner legs or at-grade level intersections are not shown in the annual report.
Prior to 2010, ramps (all types of arrangements and sizes of turning roadways connecting two or
more "legs") at interchanges or at-grade intersections are not shown in these reports.
Traffic volumes for these road segments may be obtained from the Office of Systems Planning by calling
515-239-1323 or emailing Ronald Bunting at