Road shields in turn instruction overrides
To add a road shield to an instruction, you select it from a list. That list only includes road shields from streets that are currently visible on the Waze Map Editor screen. So if a shield is missing, zooming out or moving the map will show you more shields in the list. Any changes to that road shield on the street will not change the road shield used in the instruction override as the shield is duplicated. If the shield you want to add doesn't exist yet, you can temporarily create a shield on a nearby street and then use that shield in the instruction override. Don't forget to remove the shield from that street afterwards.