there were 0.71 driving deaths per 100M miles travelled
I don’t think this is a good basis for comparison. The comparison in the tweet you link to seems to talk about commuting, so it would probably make sense to compare based on the number of trips rather than based on the miles traveled. In particular, in the data you link to, we can see that the number of car accidents from trucks is pretty small, while I would guess that truck drivers represent a bigger share of miles traveled, thus lowering the death rate per mile, without this being relevant information.
[EDIT] I looked it up
For public transit, you write (for a high crime rate city, but not the highest possible, and for an outlier year, as pointed out in another comment)
This makes sense, but going this direction gets pretty tricky. A trip that you could plausibly take public transit for is probably also the kind of relatively slow urban commute that is unlikely to result in a fatal crash. For example, I live in Somerville MA, and checking FARS we have had one car crash that was fatal to someone in the car in the last decade. [1][2]
I can’t easily find numbers on how many car trips people in Somerville took over the last decade, but back of the envelope: 80k people * an average of one car trip per day * 365 days * 10 years = 290M trips. So 0.3 per 100M Somerville MA trips? (Which is also perhaps the most literal interpretation of the “where you live” in the original tweet?)
[1] This excludes car crashes where the only fatalities were pedestrians, which I don’t like but I think is the right way to do this analysis?
[2] Going back farther there used to be a lot more. I think this is a combination of safer cars and traffic calming?
One trip per day seems very low, don’t people usually do at least two trips per day (going to work, going back home), or even 4? Are trips bi-directional (in which case I must apologize, this would be a misunderstanding on my side)?
None of this is to discourage your request that such claims be supported by sources, as a standard.
One trip per day seems very low, don’t people usually do at least two trips per day (going to work, going back home), or even 4? Are trips bi-directional?
I was counting a trip as one direction: if I take the subway to work that’s one trip, and then another when I come home. But a lot of trips won’t be car trips, and everyone has a commute, and not everyone goes out every day? So I was guessing this would average to one car trip per person per day? Though thinking more now that’s probably too low?
I don’t think this is a good basis for comparison. The comparison in the tweet you link to seems to talk about commuting, so it would probably make sense to compare based on the number of trips rather than based on the miles traveled. In particular, in the data you link to, we can see that the number of car accidents from trucks is pretty small, while I would guess that truck drivers represent a bigger share of miles traveled, thus lowering the death rate per mile, without this being relevant information.
[EDIT] I looked it up
For public transit, you write (for a high crime rate city, but not the highest possible, and for an outlier year, as pointed out in another comment)
In the US, there are about 400 billion car trips per year, and about 40k death per year, so this implies an average death rate of 10 death per 100M trips. This is an average.
This makes sense, but going this direction gets pretty tricky. A trip that you could plausibly take public transit for is probably also the kind of relatively slow urban commute that is unlikely to result in a fatal crash. For example, I live in Somerville MA, and checking FARS we have had one car crash that was fatal to someone in the car in the last decade. [1][2]
I can’t easily find numbers on how many car trips people in Somerville took over the last decade, but back of the envelope: 80k people * an average of one car trip per day * 365 days * 10 years = 290M trips. So 0.3 per 100M Somerville MA trips? (Which is also perhaps the most literal interpretation of the “where you live” in the original tweet?)
[1] This excludes car crashes where the only fatalities were pedestrians, which I don’t like but I think is the right way to do this analysis?
[2] Going back farther there used to be a lot more. I think this is a combination of safer cars and traffic calming?
I agree with you that this gets pretty tricky.
One trip per day seems very low, don’t people usually do at least two trips per day (going to work, going back home), or even 4? Are trips bi-directional (in which case I must apologize, this would be a misunderstanding on my side)?
None of this is to discourage your request that such claims be supported by sources, as a standard.
I was counting a trip as one direction: if I take the subway to work that’s one trip, and then another when I come home. But a lot of trips won’t be car trips, and everyone has a commute, and not everyone goes out every day? So I was guessing this would average to one car trip per person per day? Though thinking more now that’s probably too low?
Honestly I don’t really know