Hennepin County has more than 332,000 workers who live in a different county but commute there for jobs each day. That is among the highest number of workers in the nation who cross county lines to get to work, according to data released this week by the U.S. Census Bureau.

Of the 332,216 workers who commute to Hennepin County, more than 68,800 of them come from Ramsey County. Another 62,315 workers come from Dakota County and 61,141 commute in from Anoka County, according to 2006-2010 estimates from the American Community Survey.

"It is well known that Hennepin County draws a lot of commuters to work. The detailed information in the American Community Survey tells us where Hennepin County workers are coming from, where its residents work and how its commuting patterns compare to those of other large counties," said Brian McKenzie, a Census Bureau statistician who studies commuting. "This information shapes our understanding of the boundaries of local and regional economies, as people and goods move across the nation's transportation networks."

Heading in the other direction, more than 112,567 Hennepin County residents leave the county for work. A majority of those — 46,778 — head east to Ramsey County, while another 18,953 make the trip to Dakota County and 16,858 head to Anoka County, the survey found.

With the high mobility rate, it's not surprising that 73 percent of commuters drive to work alone. That is below the national rate of 76.4 percent.

Their average commute time one way was 22.8 minutes, compared with the national average of 25.5 minutes. But 3.5 percent had drives that averaged 60 minutes or longer.

About 9 percent of Hennepin County workers commuted in a carpool, while 7.7 percent used public transportation. Just under 2 percent biked to work, the survey found.

More than 81 percent of Hennepin County residents work in their home county, the highest number in the metro area.

Anoka County had the highest percentage of residents who don't work in their home county, with 61 percent working elsewhere. That was followed by Washington and Carver counties with 60 percent, Dakota with 52 percent and Ramsey with 45 percent.

Nationally, more than 27 percent of workers commute outside the county where they live, according to the 2006-2010 County-to-County Commuting Flows report on commutes between counties. That is slightly up from 26.7 percent in 2000.

Follow news about traffic and commuting at The Drive on startribune.com. Got traffic or transportation questions, or story ideas? E-mail drive@startribune.com, tweet @stribdrive or call Tim Harlow at 612-673-7768.