I used to think that, too. But lately, I’ve started to consider that even more people are even worse drivers than I thought. And I think that really changes things.

Also, that common airplane statistic about deaths is usually reported in terms of passenger miles, which I think is a little misleading since airplanes intrinsically travel many more miles. It would be more meaningful to measure deaths per trip or better yet deaths per passenger hour rather than miles. However, I did find some lawyer websites saying that the lifetime odds of dying in a plane crash are around 1 in 800,000,000 versus 1 in 95 for cars.

Now I know it seems deranged on the face of it, but hear me out.

For driving to be as safe as flying, we would need someone to be about 8500 times less likely to die over the course of their life driving. Most people drive 5 days a week, for about 50 years, so 13000 days driving. So:

The odds of surviving a day of safe driving= S

Odds of surviving a day of dangerous driving= D

8500=S^13000 / D^13000 = (S/D)^13000

S/D = 8500^(1/13000) = 1.0007

So if driving safer on day made you even 0.07% more likely to survive that day, then that gives us that 8500x increase over a lifetime.

Now…I know this is based on that 1/95 which ALREADY includes the safe drivers. So the legitimacy of this estimate depends on how many drivers you think are safe. This is why my estimate of that ratio caused me to change my mind. I feel like only around 15% of people drive at that level of safety. So, of course, unbalanced means that driving is more dangerous because you have an 85% chance of being one of the people for whom it is more dangerous. But I still think there’s something to be said for the minority of truly cautious and defensive drivers.

Acknowledging other failure points here, most airplane deaths are in private aviation, so that may make the bar harder to clear again. But I think the whole 13000 days estimate demonstrates how even tiny improvements there can easily account for large changes, too.