I've used Premier Limo for many years for trips from Washington, DC (Capitol Hill) to Dulles Airport, for pick ups, drop offs; for myself and visiting family. I couldn't be happier with them. They are totally reliable and are available 24 hours for picks ups and drop offs. You book your car by phone, your driver arrives on time (or early). The cars are new models, well kept and very clean. They even often have a bottle of water and a newspaper waiting for you in the car (very nice for arriving passengers). If you are doing a return trip, just give your driver your arriving flight information and a driver will be waiting for you when you get off the plane. For departing passengers, the driver collects your bags at your front door and loads them into their trunk. For arriving passengers, they meet you at the baggage collection area or, for international arrivals, at the exit from customs. They take your bags from you and walk you to their car. Their prices are flat rate and very reasonable, usually cheaper than a taxi. And Premier Limo drivers are well dressed and polite. And, unlike the majority of DC taxi drivers, they have a friendly attentive manner. Their service is excellent, I don't hesitate to recommend them to anyone looking to get from Washington, DC to Dulles Airport at any time of the day or night.