At that time Oxnard was a sleepy little agricultural town of about 25K; IIRC a bypass around the eastern side of town was planned (the usual DOH/Caltrans "circular lines" indicating a general but unadopted alignment) but obviously never saw any follow-through.
Isn't Rice Avenue essentially that eastern bypass, much in the same way Cosumnes River Boulevard going towards Freeport is an adaptation of the Route 148 corridor (in Sacramento) and Richmond Parkway is functionally an adaptation of the planned Route 93?
IIRC something similar occurred with the planned Route 126 connector between I-5 and Route 14, built out as a unnumbered boulevard.
It kind of is, but part of the problem is that Rice is a surface street. Yes, about half of it abuts farmland, south of CA-34, but if the authorities aren't on top of things, that road could become another suburban arterial filled with development and it can slow traffic down. Probably need to purchase some of that land to prevent development from encroaching on the future highway.
The substitute for the rescinded CA 126 connector in Santa Clarita isn't one continuous roadway but a series of arterials winding through Santa Clarita. The original CA 126 surface alignment, now relinquished, didn't actually efficiently work as a shunt between EB 126 and NB 14, since it turned south at Saugus along San Fernando Blvd. through Newhall, intersecting CA 14 southeast of town and not terribly far from the 5/14 interchange. The proposed (and at one time actually adopted) alignment resolved that issue; it was intended to be part of a continuous CA 126 freeway across the north side of Santa Clarita, intersecting CA 14 at the present Via Princessa set of ramps just south of 14's Santa Clara River crossing. But that alignment was severed during the 1994 round of rescindments, coincidentally a couple of years after the Metrolink Palmdale line through the area was initiated; it was widely opined that the desire to focus on transit rather than throughput roadway connectors such as the CA 126 extension doomed the freeway project -- that rationale basically continuing with the CA 1 situation. Although it's likely that Rice Ave.
will eventually see formal Caltrans adoption and signage -- if for no other reason than to efficiently feed traffic to and from PCH to the southeast, D7 probably won't be in any particular hurry to do so within the present sociopolitical climate that tends to see highly visible road connectors like this to be "enabling" the driving public to continue present patterns rather than curtail automotive use. Agencies such as Caltrans, with a longstanding connection to road network expansion tread lightly these days, especially within urban/suburban/exurban zones like the built-up areas of Ventura County.