When I map, say, bus:lanes=|designated or psv:lanes=|designated, should I also add motor_vehicle:lanes=|no or vehicle:lanes=|no (or some other value instead of no according to the local law), or is it considered implicit from designated within the value of bus:lanes?
Similarly, if I don’t add motor_vehicle:lanes or vehicle:lanes in this case, would the tagging be considered complete and correct?
Should I also preferably add an explicit yes for lanes when possible for clarity instead of leaving lanes empty? (as in vehicle:lanes=yes|no and bus:lanes=yes|designated if that’s what the local law establishes)
The no should be explicit. Otherwise, the default value for access is used which is usually yes. Overriding works top down, but not bottom up (psv cannot affect vehicle)
If others are not allowed in that lane due to the designation, then the omission would leave the tagging incomplete.
yes should only be used where it’s based on local signage or similar. If it’s just the default, leave it to the router to figure that out.
or is it considered implicit from designated within the value of bus:lanes?
Not really. designated does not mean the same as only. E.g. same lane might be designated for both PSV and taxi, but forbidden for other motor vehicles…