C.O.
The Metro is NOT under construction where you will be using it...they are expanding the metro from West Falls Church to Dulles Airport...
If you tell us/me where you are staying and when you will be here - it might help out too...what you are interested in...there's sooo much to do here!
Also - July is VERY HOT and HUMID here - please be prepared for that - July and August are our hottest months...and most crowded as well...it will get in the high 90s and low 100's with 70 to 80% humidity - I am NOT talking you out of coming - I am TRYING to prepare you for what you will encounter...
1. the Smart Card is the best thing to do...I would put $40 on each card as the fares are higher during non-commuting hours and since you will be here for 6 days - that should be plenty. You don't have to order them in advance - you can buy them right there at any metro station.
2. I don't see where metro lines are delayed...this is a TEMPORARY thing..my husband commutes on the metro EVERY DAY and has for 9 years...you are freaking over something that is going on RIGHT NOW and not while you are here..
3. I would TRUST OUR METRO!!! It has gotten me and my family to baseball games, Arlington Cemetery, the National Mall, Capitol Hill and the Smithsonian...like CLOCKWORK!!
4. You will not be able to take the metro to the Udvar-Hazy Smithsonian as it's off Route 28 South and is NOT metro accessible.
Depending upon where you are staying in DC (STAY OUT OF SOUTH EAST AND NORTH EAST - my personal opinion for living her fore 15 years)...everything is metro accessible - you are letting preconceived or even current (the day you are looking at the metro system) cloud your judgment..
The metro is easy to navigate. My best friend flies into Reagan, hops on the metro and I pick her up at East Falls Church.
The Newsuem is metro accessible (off Rosslyn) and a short walk. This gives a great history of television and news...
The Reflecting Pool is being revamped/renovated...doesn't mean you can't see the Lincoln Memorial or the Tidal Basin...there is still a ton to do...
This is the National Park website - try this and see what there is to do from this point of view...
http://www.nps.gov/nacc/index.htm