Ford Focus 2015 titanium verbal Caution warning?

I've recently bought a new ford focus titanium 2015 and from time to time when i'm driving i will get a verbal "caution" warning but nothing shows on the dashboard, i don't have the lane departure or blind spot aids fitted. What could it be?

It's a speed warning camera using the sat nav
Quote from here:
http://www.focusstoc.com/forums/topic/370602-ford-sync-2-speed-cameras/
""""Mine says "Caution" whenever I'm coming up to a fixed camera position.""""

Good to know I have the same problem.