"The Dulles airport website says:"
The Dulles Airport website has a lot of time on its hands to make the trip this way. They make it sound so simple, don't they?
First, you'd need to take the Hilton's shuttle from the hotel to the airport (10 minutes). Tip the driver a few dollars.
Then the Washington Flyer to West Falls Church ($10/25 minutes).
Then the Metro--two trains, since you need to transfer--$3.45/35 minutes.
Then the MARC or Amtrak train. $7/60 minutes on MARC to perhaps $20/40 minutes on Amtrak (MARC runs only during the week).
Then you'll want a taxi from the train station in Baltimore to the Radisson. Figure $10/10 minutes.
Adding it all up, that's about $60 for the two of you, give or take depending on whether you get MARC or Amtrak. Oh yes...let's not forget hauling, loading and unloading your two heavy bags six times between the Hilton and the Radisson.
Now let's talk travel time. If you were to make all your connections perfectly, that's about 2 hours 10 minutes give or take. But the trains and coaches don't leave every second. Here's the possible waiting time you might need to add at each stage if you're late rather than early by 10 seconds:
Washington Flyer leaves every 30 minutes
Metro leaves every 5-12 minutes
MARC and Amtrak trains run about an hour apart
It's your call, but my guess is you'll wind up at about 3 hours from the time you leave the Hilton until you reach the Radisson via transit vs. 75-90 minutes via car service or taxi. But you will be an immediate expert on most every mode of public transportation in the Washington/Baltimore area.