Limestone agg in asphalt.
 

Whilst travelling through Croatia and Turkey I became aware of the use of what appeared to be limestone aggregate in some asphalt roads. It polishes up like marble with the same lack of grip. Although I have not had any rain to talk of this type of surface is slippery whist dry let alone wet.
I did a search to see whether this topic has been mentioned before and I found this comment dated 2008.

********I agree with the previous posts - the Croatian Coast is stunning! Yes, the roads are good, but beware of corners when there's the slightest bit of rain. They used limestone in the mix for some reason which makes the road very slippery (Montenegro, too. All of the former Yugoslavia, probably.) ********

Worth taking note of. Cheers

I've noticed that when I was out there. It's done to stop the road's melting in the hot weather.
John933