Nightmare springs to mind.
So, on that basis, let's give a big hand to the following:
- Mothercare in Cardiff - "normal" cubicles big enough to push a trolley or pushchair in to.
- Charnock Richard services on the M6
- Waitrose in Abergavenny
- Morrisons in Barry, all of which have the sense to put a cubicle in the baby change room (as opposed to putting the baby change in the disabled toilets)
I thank various deities for a cast-iron bladder, and make the most of every opportunity to pee I get now, I never know when the chance will next arise!