Public Utilities Code § 29031

The district may acquire, construct, own, operate, control, or use rights-of-way, rail lines, bus lines, stations, platforms, switches, yards, terminals, parking lots, and any and all other facilities necessary or convenient for rapid transit service within or partly without the district, underground, upon, or above the ground and under, upon, or over public streets, highways, bridges, or other public ways or waterways, together with all physical structures necessary or convenient for the access of persons and vehicles thereto, and may acquire any interest in or rights to the use or joint use of any or all of the foregoing; provided, that installations in state freeways shall be subject to the approval of the Department of Transportation and installations in other state highways shall be subject to Article 2 (commencing with Section 670), Chapter 3, Division 1 of the Streets and Highways Code.