In addition to the CA 11/125/905 updates, I've just made a bunch of other changes to usaca routes, as another way to procrastinate on Christmas shopping. Many were to clear to-do list items on this forum and the old CHM forum. But I've also started on legislative relinquishments of state route segments to local governments.
The easiest ones were route-end truncations, at the west end of CA 2 in Santa Monica, east end of CA 74 in Palm Desert, south end of CA 144 in Santa Monica, and CA 170 south of the US 101/CA 134 inrerchange. In those cases, even though state law requires the jurisdiction taking over a relinquished segment to maintain signage pointing motorists to the continuation of the route, there is no (or almost no) such signage. Signage on Caltrans-maintained intersecting roads also ignores those (former) state route designations. The above truncations are just the ones I have traveled or confirmed on GMSV. I expect there will be others, given generally uneven compliance with the continuation-signage law.
Mid-route relinquishments cause more heartburn since they split routes (some into multiple pieces). I'm not sure how to handle those, though maybe bhemphill's suggestion could work for at least the shorter gaps. But I did split CA 111 into separate Calexico and Palm Springs segments, to reflect a long stretch of relinquished mileage from Cathedral City to Indio. Most of the relinquished segment has minimal continuation signage (only "Highway 111" street blades). But travelers need to make a turn in Indio onto Golf Center Parkway to follow the relinquished segment to the rest of CA 111, and there is no longer any signage indicating that. For many other mid-route relinqushments, travelers can simply continue on the same road to get from one non-relinquished segment to another, even with poor or no continuation signage. They can't do that here, so I'm comfortable with splitting at least this route.
BTW, CA 111's south end is defined legislatively at the Mexican border. But the Federales used eminent domain to take the south end from Caltrans, to facilitate expansion of the Calexico port of entry, and the HB reflects that small truncation.