◪ Jarv
There are no restrictions on any types of vehicles on Marlborough Place despite of the road markings.
If driving North along Marlborough Place you must turn right at North Road due to ahead being a virtual bus gate, making Marlborough Place useless for through traffic (except busses, taxis & cycles as they are exempt from the virtual bus gate). Likewise in the opposite direction there are no right turns from North Road and there is another bus gate along Gloucester Place.

So in short, this road is open to everyone. However cannot be used as a through route for non-authorised (bus,taxi&cycle) vehicles due to the adjacent bus gates.
It is already tagged as appropriate.