If you’re stuck in traffic on your morning commute wondering where all of those cars in front of you have come from, we may have some answers. Today, the Census Bureau released the latest county-to-county worker flow tables based on American Community Survey data collected from 2009 to 2013, which shows patterns of commuting flows for workers in every U.S. county. These tables include information on home-to-work commuting patterns by mode of transportation for U.S workers.

Every day the nation’s roads, highways and transit systems carry millions of people from home to work, often across county lines. Most people live and work in the same county, but 28 percent of workers travel to a different county for work. These tables allow you to see how many people travel into your county from nearby communities on a typical workday and how many people leave your county for others. Among other applications, commuting flow information may be used for traffic congestion relief efforts, emergency management, transportation planning and commercial development.

The tables also break down commuting flows by different modes of transportation. For example, they show how many workers take public transportation from one county to another on a typical workday. The nation’s five largest worker flows by public transportation involved workers traveling to New York County (Manhattan) from surrounding counties. Kings County (Brooklyn) sent the largest number of workers to Manhattan at 365,000.

Some of the highest rates of carpooling between counties are found in Southern California. About 24,000 workers carpooled between San Bernardino County and Los Angeles County. Los Angeles County and Orange County each swapped about 21,000 carpoolers with each other on a typical workday.

As technology, demographic shifts and other factors continue to shape travel preferences and patterns, the American Community Survey remains a valuable tool for tracking these changes across communities and over time.

For more information on commuting products, including special reports on topics such as working at home, daytime population change, and bicycling to work, visit the Census Bureau’s commuting home page