When I worked in DC, many (and my) federal buildings had bike parking right out front for a quarter an hour (best deal in town). To park your car somewhere (and then hike to work) might be $3-5K a year. But consistently riding in DC was a bit of a death wish. What with the terrible traffic and potholes, and worst of all the DC International Cab Drivers Association. Ten thousand guys who shared one driver's license, and were terrible drivers who never used the brakes, only the horn. I worked with a guy (computer fixer dude) that rode daily and he was hit and knocked off his bike three years in a row. And the exit off the meandering GW Parkway at 35mph up onto the I-395 bridge across the Potomac into DC (70MPH traffic) had a very short ramp and was really exciting and scary (even with Valkyrie power).
Thus my 18 year saga of riding the Metro train.