This page includes data that provide two perspectives on transportation systems. The first data set, from the U.S. Census Bureau, includes data on the usual mode of transportation to work for workers age 16 and older. Alternative commute modes include all means of getting to work except driving a car, truck, or van alone. The second data set is from the American Public Transportation Association and measures the frequency of public transit use in terms of unlinked passenger trips per capita. Unlinked passenger trips are defined as the number of passengers who board public transportation vehicles. Passengers are counted each time they board a public transportation vehicle no matter how many different vehicles they use to travel from their origin to their destination.