I found this little link the other day whilst looking for the Spanish version of the UK-based IAM (Institute of Advanced Motorists). I find it relevant since the exact same scenario occured when I approached a roundabout and had to brake sharply for (yet another) suicidal motorist who doesn't know where his indicators, mirrors or brakes are.
The interest to me was that the front tyres were new and the road conditions apparently very good, being dry and sunny with an ambient temperature of over 30 degrees C. Nonetheless, on braking, my car slewed sideways as I had already started to turn into the roundabout. Thankfully, the braking distance was so short I was able to stop before the give way lines on the roundabout.
Oh, and by the way, there is no equivalent to the IAM in Spain - ¡que sorpresa!