Originally Posted by
Often1
The plan is too ambitious even though you should have a great deal more time than you state.
Parking in DC is brutally expensive, when it is available at all. Most garages charge the full daily rate after an hour (anywhere from $25-50). As you move around, you will be paying that several times.
A better plan is to grab your luggage and then Uber to a hotel nearish to the first place you are headed. Drop your bags there (a very nice tip to the bellman will do it). Should run you about $15 into DC.
You have not told us what carrier you depart on, but I cannot imagine a reason to be at IAD 3 hours prior to departure unless you are planning dinner out there. Allow yourself 1:15 (0:45 + rush hour). Uber back out to IAD will run around $40 (Maybe $45 depending on where you are when you need to swing back to the hotel to pick up your bags).
You can use Uber, the Circulator bus ($1), or Metro ($2.25) during the day if walking isn't in the cards.
All of this will be more pleasant and cheaper than worrying about parking and waiting for your car to be brought around.
I generally concur.
Note that the Capitol to the Lincoln Memorial is a large area to cover. In addition, if you plan to go in the Capitol, you need to go through the visitor's center, located on the far side of the Capitol...may be time consuming.
Restaurants - many good places to eat, but most are several blocks off of the National Mall. If sightseeing is your objective, then I'd just grab a bite to eat in one of the many museum cafeterias rather than backtracking.
But if you want to eat at Washington landmark, at a reasonable price, I always recommend the Old Ebbitt Grille near the White House.