Anything in particular that needs to be field checked?
I'd need to compile a list of the mid-route relinquishments in Los Angeles and Ventura counties, and maybe some adjacent counties, I haven't already field-checked in my recent travels covering most of the rest of California. (Whole-route and end-of-route relinquishments are easier, I'm presumptively treating them as decommissions/truncations). That means a review of the legislative route definitions in the state Streets and Highways Code (the California Highways website quotes the key provisions). Also, using Caltrans' Postmile Query Tool to help determine which relinquishments have been carried out (like CA 187, already removed from the HB), and which might never be carried out much as the legislature might want them to happen.
The California Highways site can help narrow what needs a GMSV review, but I know what to look for. Once that's done, the GMSV review is tedious but easier to hand off.
Quebec does relinquishments too, but normally leaves locally-maintained segments in the provincial highway route system. That made my life easier when I finalized and activated canqc.
^ The main rub is nailing down whether we need to break up routes that have been partially relinquished to local jurisdictions
I vote no.
Mid-route relinquishments do come with legal mandates for the local jurisdiction to continue signing the route. Said jurisdictions aren't always good at complying with these mandates but... nonetheless, it's functionally no different than the existence of locally maintained sections of route in any other state. CA just has an oddball way of handling it administratively.
Except where Caltrans posts an END sign at one or both ends of the relinquishment, as with the End CA 160 sign assembly at Sacramento's southern city limit. Or where the local government not only fails to maintain route signage, but that makes it difficult for motorists to follow the (former) route winding through a maze of city streets (like CA 160 in downtown Sacramento -- though some of the former route there has excellent Historic US 40 signage -- or CA 79 in San Jacinto). Or where the state has non-standard continuation signage mandates, like in Hayward which had several surface routes passing through the city, but now looks to motorists like a big hole in the non-freeway part of the state highway system.
I don't know whether or not will be similar issues in the Los Angeles metro area, but I think I've addressed them in most of the rest of California.
