prevent
an
enhance
ABS will help if your descending on an icey road and are avoiding locking up the front wheels (not at all handy).
I got snowed in once and tried driving down this mountain road in a '84 Nissan Bluebird S/Wagon. I made it by leaving the vehicle in 1st gear (manual or stick-shift) and using the handbrake only as I knew once I locked the front wheels it was "in the ditch" or into the Armaguard-railing time.
Jason