According to a 2010 study, Washington-area commuters spent 70 hours a year in traffic delays, which tied with Chicago for having the nation's worst road congestion. However, 37% of Washington-area commuters take public transportation to work, the second-highest rate in the country. An additional 12% of D.C. commuters walked to work, 6% carpooled, and 3% traveled by bicycle in 2010. A 2011 study by Walk Score found that Washington was the seventh-most walkable city in the country with 80% of residents living in neighborhoods that are not car dependent. In 2013, the Washington-Arlington-Alexandria metropolitan statistical area (MSA) had the eighth lowest percentage of workers who commuted by private automobile (75.7 percent), with 8percent of area workers traveling via rail transit.