A number of stores here in Kitchener (Canada) use the single queue approach, particularly to feed a bank of self checkout stations. But I've also seen it at Old

A number of stores here in Kitchener (Canada) use the single queue approach, particularly to feed a bank of self checkout stations. But I've also seen it at Old Navy (clothing), Winners (discount clothing), Indigo (bookstore), and others. I think the main thing that's maybe a bit annoying is just that it's easy for the single line to stall if the people at the front of it aren't paying attention or don't know what to look for. So the store often ends up having to have an extra attendant who just stands there and pokes people for when a till comes available.