I have no idea what the best route is, I usually take the Jersey
turnpike to I-95.  (I have to travel to Florham Park, NJ a couple times
a year, but I usually just go the way I know.)  I've been told there's a
back way that takes you through PA near Reedsville and you end up taking
83 to 81 to 270 (or stay on 83 through Baltimore and pick up I-95 there)
but I've never done it that way.  Probably a much less stressful drive,
for sure.  If it is easy for you to get to I-83 from NYC that might be
your best bet, although I do like the courtesy of NJ drivers (when
traffic isn't stop and go that is.)  I couldn't believe it when people
actually started pulling right to let me pass them!  Unheard of here.

By the "new air museum" I ASSume that you are talking about the SI annex
at Dulles, that is a decent hike outside the city, and the Metro doesn't
go that far so you will have to drive.  I think it's a good 30 miles or
so.  Also be aware that I-66 is HOV only inside the beltway, inbound in
the morning and outbound in the afternoon, so if you're going take Ellen
with you or plan an alternate route.  (or leave for Dulles in the AM and
go back into the city in the PM.)

Where exactly are you guys going to be?

nate

Bill,
Can't help you with the best route. Try Mapquest but double check the
directions. I was just at the new air museum. I highly recommend it. It is
out at Dulles Airport. Lots of flying devices but the highlight is the Enola
Gay the Enterprise and a Blackbird. Many one of a kind airplanes.
You will enjoy the day there.
Mike Williams

   I don't know "the best" but most everyone comes down 95 South.   I
also don't know about a new museum, but the Air and Space museum is a
must see.
 http://www.nasm.si.edu/

95 is your most direct route, but can be kind of "white knuckle"
traffic-wise and is subject to unexpected backups.  Where in DC (or the DC
area) does she have to come?  To get to Udvar-Hazy from DC, take I66 West to
VA 28 at Centerville.  Go North on 28 probably five miles and watch for the
exit to Udvar-Hazy (there is nothing else around).  There are some more
direct routes, but they involve toll roads, HOV lanes and switching
highways.  Admission is free, but they charge $12 per car for parking.  It
is an incredible place- not only a huge number of special airplanes, but
many pictures and a very large number of old aircraft engines.  You can go
up in the tower and see all of Dulles, but they do it by tickets (free) and
the lines can be very long.  Be prepared to have VERY TIRED feet.  Depending
on traffic, from downtown DC it should take about 30 minutes to get there.
With your aviation background you should find this museum especially
fascinating.
Enjoy,
Paul Johnson

Fly into Dulles...  The museum is adjacent.

JT

Take I-95 south to I-495 (western loop around DC)
Air museum new building is out on the Dulles airport property about 15 miles
west of the capitol.
Signs mark it well.
See both buildings though... They are worth the walk.
Jeff