The League of American Bicyclists started Bike-to-Work Day in 1956 as a part of National Bike-to-Work Week, which in some cities has turned into Bike Month.Bike-to-Work Day is an annual event that promotes and celebrates the bicycle as a viable mode of transportation. On Bike-to-Work Day, national, regional, and local bicycle advocacy groups often organize bicycle-related events.Today's Streetfilm features Bike-to-Work Day in Austin, San Francisco, New York City and Portland, Oregon.If you haven't already, check out the Streetsblog open thread from Friday. And, contact us if you would like to participate in next year's NBTWD film!