The purple section, which is a new road, allows for passenger drop off at the front door. Continuing on, the first parking lot with the green dot will hold 250 cars. Continue on to MLP-8(multi-level parking) garage, next green dot, will does hold 1400 cars. Next to MLP-8 is MLP-6 can hold 710 cars.
Parking..in short - don't park in handcap, fire lane nor loading dock...just about everything else has no restrictions. STOP for pedestrians in crosswalks or you will be ticketed.
Open parking on weekends was one of the advantages I knew of back when talk of a conference was first started.
Latest information on the Masur Auditorium: Because of construction, the roads around NIH are in a continual state of flux. If you haven't visited the campus lately, there are no longer any parking lots out in what used to be the front (the side closest to Cedar Lane).
You can still get to the parking garage from Cedar Lane (Cedar Lane is the northern boundary of the NIH campus). Turn at the light at West Drive. Go left at the stop sign. Turn right at the next stop sign. You will be able to get into the underground parking garage. See below for more details.
You can also enter from 355 at the Medical Center Metro stop (South Drive). Go straight through the first stop sign (a 4-way stop). Turn right at the next stop sign and look for parking garage P3 (patients and patient visitor parking). Park there and take the elevator to the first floor of the Clinical Center. If you arrive before 7 pm on a weeknight, you'll need to take a ticket for the garage, but if you leave after 7:30 pm, you won't have to pay.
You may also park in the new "front" lot for Building 10. To get there, follow the above directions from Rockville Pike. Instead of turning right at the 2nd 4-way stop, go straight. At the next 4-way stop, you will be able to see the front of the building. Turn left and then right at the next stop to circle around to an entrance of the new parking lot.
Directions from the Metro: get off at the Medical Center stop on the red line. Walk west (away from 355/Rockville Pike) on South Drive. Stay on that street (you'll need to cross over to the right side of South Drive because the sidewalk ends on the left side) and after the third stop sign, you will come to the new entrance of the Clinical Center (Building 10) which will be on your right. Follow the signs to the Masur Auditorium or stop at the help desk.
Parking restrictions: summing up a conversation with the NIH police; on weekends and holidays there are no restrictions beyond handicapped spaces. On weeknights, the front lot of Building 10 (of what used to be the back for us old timers) is open season after 7pm at night. After business hours, parking garage P2 and P3 have no restrictions beyond handicapped spaces. The Masur Auditorium is on the first floor--same as the front entrance. If you park in the parking garage, go to 1 and follow the signs.