PSST 2019 will be held on the second floor of Aaron Burr Hall, in room 219. Aaron Burr Hall can be found on Google Maps here: https://goo.gl/maps/TZsfANd4kME2, and the map below shows the location of the entrances (one at the arrow head, and one at the red X).
Each of these lots is about a 15-20 minute walk to Aaron Burr Hall. Additionally, on Friday, there are regular campus shuttles (“TigerTransit”) that can bring you to close to Aaron Burr hall. (The ‘A’ Central Line goes from Lot 20 to Firestone Library, and the ‘C’ East Commuter Line goes from Lot 21 to the Friend Center. Details at this website.)
For Saturday, all numbered lots on campus are available for visitor parking. Lot 10 (https://goo.gl/maps/jJhaD7RA9Lk) and Lot 13 (https://goo.gl/maps/Y7pPcNNBvrQ2) are located very near to Aaron Burr Hall.
Princeton campus is also accessible by NJTransit. You can reach Princeton by taking the Northeastern Corridor Line (connecting Trenton and New York Penn Station) to Princeton Junction station. Princeton Junction is about 10 minutes by car from Aaron Burr Hall (there is a taxi line on the north side of the train tracks at Princeton Junction). You can also take a bus to Princeton Station. Princeton Station is about a 15-20 minute walk to Aaron Burr Hall. (On weekdays, instead of walking from Princeton Station, you can also take the TigerTransit ‘A’ Central Line to Firestone Library.)