I commute along the Potomac River to Southwest DC on the Mount Vernon Trail, with some lightly travelled streets near home, in Old Town Alexandria and in DC.
I began occasional commutes using a Trek 1200 racing bike, a fast but somewhat harsh ride, especially after lower back surgery. I switched to a Specialized Sequoia, a touring bike with fenders and a generator light. After a few years I ditched the generator and started using a Nite Rider Digital Headtrip mounted on my helmet. A couple of years ago I treated myself to a Brooks leather saddle with springs. Last year my Sequoia began to show signs of age. After trying to find a sturdy bike that would cover 29 miles and be kind to my back, I bought a Tour Easy Expedition recumbent. For visibility I have an Illuminite vest, tires with reflective sidewalls, a blinking red light for visibility to the rear, a handlebar mounted light, flashing lights on the stems of my tires, and reflective tape on my bike bags.
My wife and I work in the same office in DC. On 9/11/2001 we were evacuated shortly after the Pentagon was attacked. I jumped on my bike and, after being diverted by police upriver toward the burning Pentagon, I headed downriver toward home. At National Airport, I met I nice police woman carrying what appeared to be an elephant gun. She requested that I cross over the GW Parkway instead of using the bike path near the terminals. I portaged over a double guard rail, and waded through heavy traffic. Then I rode on the grass past scores of flight crews who had been evacuated from the airport. I watched as a fighter jet, fully armed, flew at low altitude overhead, through the plume of smoke rising from the fire. After about 90 minutes of this madness, I arrived at home. My attractive next door neighbor whose husband worked in the Pentagon looked up from unloading groceries from her car and said "Am I glad to see you!" I thought, "What an odd thing to say." Then I realized that her husband was a bike commuter too! She had not heard from him and mistook me for him. He was unharmed in the attack. My wife arrived home (a 30 minute drive on a normal day) after 5 1/2 hours of gridlock.
Some things I don't like about my commute: ice and snow on the ground (I don't ride), lightning, and code red (really bad air quality) days. Cars are rarely a problem. I have had one run in with a dog. And not one traffic jam.