I just changed it from the obviously wrong tertiary, so feel free to change to something more appropriate. Service road perhaps?

The tag maxspeed:type=GB:nsl_single identifies the road as being subject to the national speed limit, and as such indicates lower speed limits for different classes of vehicle. It is not required for extra tags for buses, HGVs etc to be added to every single road.

Hi, you don't need to add these. The maxspeed:type tag implies national speed limits for other classes of vehicles.

Hey, make sure to add maxspeed:type tags when adding/updating maxspeed tags. A list of maxspeed:type tags is available on the wiki here: osm.wiki/Key:maxspeed:type#United_Kingdom.
Also please don't split ways at junctions to add speed limits like this: osm.org/way/1373475907. It's best practice not to add such small segments when the speed limit is different on the main road. Cheers.

Hey, please remember to add maxspeed:type tags when adding maxspeed tags

Hey, please update maxspeed:type tags when updating maxspeed tags. Thanks!

Hi, I've updated the maxspeed:type tags to the correct value for 60 mph. If you need a guide for the tags to use, the wiki has the appropriate tags listed. Cheers!
osm.wiki/Key:maxspeed:type#United_Kingdom

Hi, please make sure to update maxspeed:type tags when changing maxspeed tags. Thanks!

Hi, please add maxspeed:type tags if you are adding or changing maxspeed tags, makes sure the type of limit is known.

Hi, please do not tag roads passing under bridges as tunnels.

Cheers

Hi, please update the maxspeed:type tag to construction if this is a temporary limit

Why did you change the highway tag on these roads?

Red route road markings do not denote a trunk route. This road will soon be trunk however due to the Silvertown Tunnel opening soon. Also, please do not use trunk_link on roundabouts.

Some of these edits are unfinished - please make sure all edits have correct tags and geometry when finishing.

Please, if you are splitting ways at a tiger tail diverge/merge, update the tags as appropriate.

If that's the case then why did JOSM update to highlight missing markings tags as a warning? For the latter, that's also not impossible, but certainly uncommon

Perfect, nice.

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: osm.wiki/Key:maxspeed:type#United_Kingdom

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