I used to do bus shelters 125 a week some weeks up to 200 for 5 years and now just won a 3 year contract with my local council for there non add bus shelters.
It would be cleaning of glass and wiping down of metal work.
cleaning the seat, clearing up broken glass if bus shelter gets smashed up,Sweeping out bus shelter and removal of grafitti and flyposters.
The one's i have must be done traditional as that is what the council want.
And i do the roofs one's a year inside and out with WFP.
Im not saying what i charge.
But on average its about 15 minutes a shelter to clean.
Some will take 5 minutes others half hour if covered in grafitti.
Also be careful what graffit remover you use some will make perspex go cloudy and then you will be charged for a new piece of perspex and some also damage the paint on the metal work of the bus shelters.
Also you may need flashing roof lights for when you are stopping at bus shelter i do as again the council specified this also hi vis clothing, glasses for when you use grafitti remover.
Hope this helps