After being caught up on the I-295/MD 295 multi-mile back-up because of the soccer game at RFK that I didn't know about, I ran into another multi-mile morass of construction involving much of the southern and western parts of the beltway (
Virginia HOT Lanes). Four lanes, I believe, were squished into one or two lanes on the inner loop. Although it was Saturday (afternoon), it was impossible to exceed 10 mph (when the traffic moved!) from the end of the I-495/295 junction to VA 7, where I gave up and got off.
If you can't stand sitting in slow interstate traffic, I suggest the following:
-Drive on I-95 north to the Fairfax County Parkway (VA 7100), exit 166B.
-Go to VA 7 west (Leesburg Pike)
-Go to U.S. 15 north. Eventually it intersects with I-70 in Maryland.
Study the online maps of the areas immediately to the east of Dulles International. There a few alternatives that you can use to go north faster, such as a possible combination of I-66, Sully Rd. (VA 28) and the Dulles Greenway (toll).
Many segments of the simpler, toll-free directions I gave above have a speed limit of about 50 mph or more: the Parkway, from what I see when I passed it on VA 7 and on Google, appears to be an interstate-like expressway; while Leesburg Pike has many 50 mph segments. U.S. 15 is a rural route with mostly a 50-55 mph (or more) limit and few traffic lights.
Taking the scenic route affords more time to pick from a more diverse market of supplies; have meaningful, inexpensive rest breaks, etc.