(a) Route 84 is from:
(1) Route 1 near San Gregorio to Route 101 at Woodside Road in Redwood City.
(2) Route 101 at Marsh Road in Menlo Park to Route 880.
(3) Route 880 to Route 238.
(4) Route 238 to Route 680 near Scotts Corners via the vicinity of Sunol.
(5) Route 680 near Scotts Corners to Route 580 in Livermore.
(6) Route 580 in Livermore to Route 4 near Brentwood.
(7) Route 12 at Rio Vista to the southerly city limit of the City of West Sacramento.
(b) The relinquished former portion of Route 84 within the City of West Sacramento is not a state highway and is not eligible for adoption under Section 81. For the relinquished former portion of Route 84, the City of West Sacramento shall maintain signs within its jurisdictions directing motorists to the continuation of Route 84.