U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Based on preliminary reports from the State Highway Agencies, travel during September 2021 on all roads and streets in the nation changed by 7.9% (19.5 billion vehicle miles) resulting in estimated travel for the month at 266.7** billion vehicle-miles.
This total includes 83.9 billion vehicle-miles on rural roads and 182.8 billion vehicle-miles on urban roads and streets.
Cumulative Travel changed by 11.7% (244.0 billion vehicle miles).
The larger changes to rural and urban travel are primarily because of the expansion in urban boundaries reflected in the 2010 census. Travel estimates for 2014 and beyond will also reflect this adjustment.
Travel for the current month, the cumulative yearly total, as well as the moving 12-month total on all roads and streets is shown below. Similar totals for each year since 1996 are also included.
Traffic Volume Trends is a monthly report based on hourly traffic count data. These data, collected at approximately 5,000 continuous traffic counting locations nationwide, are used to determine the percent change in traffic for the current month compared to the same month in the previous year. This percent change is applied to the travel for the same month of the previous year to obtain an estimate of travel for the current month. Because of the limited sample sizes, caution should be used with these estimates. The Highway Performance Monitoring System provides more accurate information on an annual basis.
** System entries may not add to give "All Systems" total due to rounding for Page 2 to 8.