The Metro Headquarters Building is located at the northern end of the plaza.

Amtrak California operates several routes under the Amtrak Thruway brand from dedicated bus bays at the north side of Union Station, near the Subway sandwich shop, not from the Patsaouras Transit Plaza, which is on the other side of the facility.

A new transitway station for the J Line and other transit buses operating on the El Monte Busway, including the Silver Streak, was built south of the Patsaouras Transit Plaza in the median of the El Monte Busway, after years of delays and budget increases.

[2][3] A bridge allows for passengers to walk directly from the Patsaouras Transit Plaza to the busway station, thereby eliminating a long, convoluted walk across the Union Station property to the former stop located on the El Monte Busway at Alameda.

Work on the station was halted on April 24, 2018, when archaeological and Native American artifacts were discovered at the site.