California Code, Streets and Highways Code - SHC § 354

(a) Route 54 is from Route 5 near the Sweetwater River to the southern city limits of El Cajon.

(b) The relinquished former portion of Route 54 within the City of El Cajon is not a state highway and is not eligible for adoption under Section 81.

(c) The City of El Cajon may not impose any special restriction on the operation of buses or commercial motor vehicles, as defined in paragraph (1) of subdivision (c) of Section 34601 of the Vehicle Code, on the relinquished former portion of Route 54 if that restriction is in addition to restrictions authorized under other provisions of law.