Not strictly required but very good practice and informs of exactly what type of speed limit is in place. A breakdown of the different values is here: maxspeed:type=*#United_Kingdom

Hi, please remember to add maxspeed:type tags when adding maxspeed tags. Thanks!

Hey, please remember to add maxspeed:type tags when changing/adding maxspeed tags. Thanks!

Hey, make sure to use the highway_authority_ref tag for road numbers, not the name tag.

Again, I wouldn't be surprised if all those brackets are botches, unless Swansea Road from the A470 to Baverstock Junction is made an A or B-road, which I highly doubt.

So would you like to change way/1283395949 and other associated ways to trunk_link now then?

Trust me, as an expert in traffic signs, and having designed a few myself in the past, you can't trust those alone as a source. Fine leave it for now, but no doubt it will be changed back upon roadworks completing.

Knowing sign designers, it seems many don't understand how brackets work. Signs alone isn't a valid source.

If you want to be pedantic, then yes, but for ease of routing during the roadworks I have switched it to secondary now (the more likely route for this road, I doubt it will go to Swansea Road). Being pedantic means also changing the ramps on this interchange and others to trunk_link now, but for ease of routing trunk is used along with the road name.

I believe having raised this there is now a warning message for such values.

Technically yes, but for simplicity the standard is as per the link. It's also perfectly feasible to map a crossing like this I believe way/1029898994.
If you want to raise anything in the discussion go ahead, just thought I'd mention it.

Have you seen this discussion on this topic? https://community.openstreetmap.org/t/where-does-a-motorway-begin-and-end/117844

Are you sure the A38 between Carminow Cross and Callywith Junction is primary (highway=trunk)?

Hi, please remember to change maxspeed:type tags when changing maxspeed tags

Hi, please remember to change maxspeed:type tags when changing maxspeed tags

Also, do the turning restrictions at the southern end of the road actually exist?

Hi, the correct tag for this is maxspeed:type=GB:nsl_single on way/169769947. Also, why tagged as a track if paved, and why access=destination?

Hi, please remember to change maxspeed:type tags when changing maxspeed tags.

I am pretty sure the speed limit on these roads is not 60 mph?

Hi, please remember to change maxspeed:type tags when changing maxspeed tags