In 2012, the average number of deaths per day in the USA by motor vehicle was a touch under 100, not even close to "hundreds." And talking worldwide, it'd be much more accurate to say thousands--about 3k per day.
To your broader point, I'd be curious about how many accidents occur because of exceptional or long tail situations versus the everyday. Long tail happens more rarely, but presumably is also much more dangerous per unit time or unit distance. I think autocars will handle both sooner rather than later, but there will be a period where they outperform human drivers on the everyday (AFAIK, that may be now or very soon) while being inferior, probably even substantially inferior, in exceptional circumstances. Will the sum of net deaths of those two regimes be positive or negative?