The buses are equipped with a state-of-the-art technology. Guided commentary is provided throughout the tour. Enjoy the views from the open top double- decker observation level or the comfort of the climate controlled lower level cabin. Either way, this tour allows you to enjoy Washington DC at your own pace and explore your areas of interest.The double decker bus departs Union Station every 20 minutes giving you plenty of opportunities to explore each stop in detail. If you were to stay on the bus for the entire loop, it would take approximately 2.5 hours.