xkcd #2940: Modes of Transportation
Title Text:
My bold criticism might anger the hot air balloon people, which would be a real concern if any of them lived along a very narrow line directly upwind of me.
alt-text:
A chart that categorizes various modes of transportation based on their practicality and danger level:
Zone of Practicality:
- Trains
- Airliners
- Boats
- Walking
- Cars
- Scooters
- Bicycles
Zone of Specialty and Recreational Vehicles:
- Motorcycles
- Helicopters
- Light aircraft
- Go karts
- Skateboards
- Rollerblades
- Skis
- Unicycles
- Sleds
- Bumper cars
?????:
- Hot air balloons
“Hot air balloons are the optimal mode of transportation, if your optimization algorithm has a sign error.”
I think I get what the guy is trying to say. Per journey, air travel might indeed end up being statistically less safe (how many times a year an average person flies vs. how many times they drive their car) but of course the question is whether that particular metric is any useful. Surely if you replaced all airplane trips with car trips, more people would die.
This Wikipedia article contains a table, which if true, confirms it:
https://en.wikipedia.org/wiki/Aviation_safety#Transport_comparisons
If you sort it by Journeys, you'll find that 117 people die in an airplane per billion journeys, while only 40 die per billion car journeys. But the article points out exactly what I said before.
Funny example that illustrates how important the choice of metric is, is the Space Shuttle which is statistically incredibly unsafe per journey (17,000,000 deaths per billion journeys) and even per hours (only skydiving coming first by a small margin) but is safer than bicycles and only twice less safe than cars per distance traveled because of those insane distances it covers in orbit.
Edit: Not that I do not know whether the table counts only commercial flights or all airplane/helicopter journeys. And also the statistics is pretty old (1990-2000) and only covers the UK, so you may still be right and commercial air travel in the last decade might be safer per journey than cars globally. Can't find a better statistics.