Is the road a part of this park?

No, the park contains the walkways along either side of the road bed.  Look for the special brown pavers on the sidewalks to determine whether you are in this national park site. 

What else does this park contain?

The park administers and/or coordinates activities at several memorials and buildings along the Avenue.  In fact, the United States Navy Memorial, Freedom Plaza, The Old Post Office Tower, the American Expeditionary Forces Memorial, and Pershing Park are all part of this national park.