It's understandable that issues pertaining to trash are going to be a bit more contentious in the UK because you're dealing with a smaller landmass area and so space for disposal is going to be at a premium. Things would likely be similar here if the USA was considerably smaller. We have the multicolored recycle bins here in Washington State as well, but that sort of thing will typically vary by city, county or State.
Regarding the plastic grocery bags, I confess that I'm puzzled over one thing, perhaps you can help. I'm wondering how the plastic bags have become a litter problem to begin with? If one traces the typical journey of the plastic grocery bag, it starts out at the grocer's where the vivacious young lass fills it with all of the goodies that you've picked out in the shop. She hands it to you with a comely smile and bids you good day, and you eventually find your way back home with it, bring it indoors and proceed to consume the contents right away or fill your fridge with it. The bag itself once empty is commonly used as a wastebasket liner, and when it's full it gets placed in the wheelie bin outside. I must say that I'm baffled as to how so very many of them have apparently gotten out onto the streets in the UK, as whenever the bag is outside it's filled and fulfilling a useful purpose. I haven't heard of any such problem with large numbers of empty plastic grocery bags littering the streets here in the USA, and I'm wondering what's going on with that that's so different across the Pond.
The problem I am talking about is usually in lay-bys on major roads, where they are left on the grass verge at the side of the lay-by by a motorist who has put little rubbish in it, it gets picked up by the winds and tossed about until they stick to a tree and get impaled, where they look awful.
Town or city wise, the plastic bag litter isnt caused in homes (except in poor areas where lazy idiots dont care about litter), any litter might be caused by businesses (shops,cafes etc) using small plastic bags and not sealing their big bins securely or having them pecked at by birds, who might rip open a bag and the contents
Stoat, dont worry,Scotland isnt a rubbish tip....lol. Although we, like most of the west, could do more to take pride in our towns and cities re litter (the younger generations are bad, the 21st century laissez faire attitude that the west seems to have about life now)
Litter is a bug-bear of mine, thats all.