Rainy days notwithstanding, spring is usually a good time to hit the road with a bicycle. But according to Timothy Sheen, of the Lackawanna Bicycle Club in Dunmore Pennsylvania, there's almost always time to hop on a bike.

"Around here, depending on the snowfall, you can ride many months of the year," he says. "At least nine." Sheen says for many bicyclists, Bike to Work Day doesn't just come once a year. "They do it on a regular basis. They don't wait until one day in the month of May."

Sheen says Bike to Work Day is a good way to promote bicycles as healthy and environmentally-friendly alternatives to cars, but there are always good reasons to ride a bike. "For short distances, you can do it by bicycle," he says. "You don't need a 5,000 pound SUV to go half a mile to get milk. You can get your exercise and get your milk, too."

Sheen also points out that bicycling is a low-impact form of exercise, making it an enjoyable activity for people of all ages.