California Code, Streets and Highways Code - SHC § 1400

(a) The construction of a bridge.

(b) The reconstruction of the existing bridge or its replacement by a new structure.

(c) The rebuilding of the bridge at another location.

(d) The joint use of the resulting bridge thereafter by such person and the public.

(e) The apportionment of the expense of any bridge work between each of the counties and such person jointly using or to use the bridge.  In no event shall either county agree to contribute more than one-third of the expense of construction, reconstruction, relocation, replacement or repair of any such bridge.

(f) The construction and use of the bridge in the manner and upon the terms and conditions agreed upon between such counties and such person.