I'm so glad to know this! Hubby and I have been wondering why we put all our money in the bin ask for a round trip and are issued a single ticket. We have been charged more and less depending on the driver and are terribly confused why no one issues round trips. Guess its simple that we should just purchase one way, in the states round trip was slightly cheaper.
Also I'm glad they dont push the button all the time, we were on the bus the other day and a elderly person pushed it..i nearly peed my pants it was soo loud!
In Glasgow, you can buy a 'Day Ticket' on the bus, which is (obviously) good for multiple trips all day. Just say 'day ticket' to the driver, and you'll just be issued the long paper ticket as normal, but it will have 'day ticket' printed on it. That's really the only form of 'return' ticket you can get in Glasgow. Oh, i'd better add, that's for First buses... i dont know what they do on the Arriva buses.
Also, in some cities, like Edinburgh and (i think London, last time i was there) it's a flat fare, no matter if you're going just one stop or all the way across town. In Glasgow, the buses are on fare stages, so you actually have to tell the driver where you are going (you dont need to bother saying 'single to', cos it's always a single--- just say 'Paisley Road Toll, please, or Kelvinbridge subway' or wherever it is you're going... if it's vague, they will ask you to be more specific), and he will then tell you how much the fare is.
But the Day Ticket makes that so much easier (and cheaper if you are doing more than 2 journeys). With the day ticket, you don't have to say where you are going, you just clearly display the ticket to the driver, and board.
Some of the Glasgow folk can advise if the info i've given you is not correct.... when im in Glasgow, i usually just buy a single, so have not bought a day ticket in Glasgow for a couple of years.