Alhamdu lillah (something like "The praise belongs to God") is a very common phrase here. You use it when things go well, when you are asked how you or your family is, etc. I've gotten in the habit of saying it a fair bit myself, even when I'm back home in the US.
You see these words on lots of U-turn signs here in Al Ain, and whenever I see them I always wonder a couple of things, but then it slips my mind and I forget to ask my co-workers:
1. Who puts these up? I mean is it something that comes pre-printed on the sign straight from the factory and is there when it is put up or does someone slap a sticker on after it has been up for a while?
2. Why U-turns? Is it just because there is so much blank space or is this a common thing to say when making a U-turn?
Of course, then there is this one that is by Al Ain Mall that for some reason is written in Latin characters (and weirdly mis-transliterated, by which I mean I have never heard anyone pronounce this with an "o" sound):
I think that the green above the truck says "Allahu akbar" (God is greater or greatest) and the red says "la tanas dhakir Allah" (my very bad transliteration), which a co-worker told me means "Don't forget your obligations to God".