"How can we avoid such accidents?" - Accidents? What is it with all you people that keep using the word "accident"? At a minimum, this incident was gross negligence / dangerous driving by the first driver and proven DUI by the second.
WTF makes it an accident? Why are there so freaking many apologists on these boards that [almost always] want to give the benefit of the doubt to the motorists?
If you all have even the slightest desire to do yourself and the cycling community any help whatsoever - then try to correct the incessant use of the term "accident" by others.