Fire? Line up here please...

I came across this at Foresterhill this afternoon. It reminded me a little of road signs in the USA, where several numbered highways run concurrently over the same physical section of road.

It opens up the intriguing possibility that in the event of a real fire, the building occupants, having evacuated the premises, would actually line up in neat single file in front of this sign according to which category of building user they belonged to...