i've been practising my driving down country lanes as i have my test soon. But get confused down country lanes where the spped limit changes alot. it would start as a 30mph zone then there will be no signs, no street lights but the word 'slow' written on the road...what is the speed limit?? obviously i wouldnt travel at 60mph down these roads as i wouldnt think it would be safe to do so (with my limited experience of driving down these roads ) but on my test i don't want to be speeding if its a 30/40 mph zone with no signs down?? HELP!!!