This is a common question among travelers who want to know the approximate time it takes to travel from Philadelphia to Washington, DC, by car, train, or bus. If you're driving, it usually takes 2-3 hours to complete the 140-mile journey on I-95 South, depending on traffic conditions and the time of day. Taking an entire train ride can be a faster and more comfortable option, with Amtrak's Acela Express service taking only 90 minutes and their regular service taking around 2 hours and 45 minutes. Finally, buses provided by other bus companies travel such as Greyhound or Megabus will take about 3-4 hours for the return trip, depending on traffic and bus route itself. Ultimately, the length of your bus trip's train journey from Philly to DC will depend on the mode of transportation you choose and the conditions on the road, bus driver or rail on the day of your trip.