Just released by the US Secret Service, here is the transportation plan for the upcoming Presidential Inauguration. The details in this document are mostly about street closures at various locations around the DC area. But it is interesting information for those who will brave the crowds to attend!
https://www.secretservice.gov/data/events/2017-Inaug/JIC-01_PressRelease_TransportationPlan-Final_USCP-1-6-17.pdf