Most Dangerous Means of Transportation?

[qpw3141]

@Chronos

Of course it takes into account the journey length. That’s what the “per mile” is.

Ye Gods! :rolleyes:

I wasn’t complaining about using ‘per mile’ for the number of fatalities per mile. I was complaining about using the ‘per mile’ measurement as the sole criteria for the headline: ‘Walking is the most dangerous form of transport’.

Think of it this way: I have to get from Point A to Point B, and I want to get there as safely as possible. Should I say “Well, people don’t often walk from A to B, so that’s the safest”? Of course not. The distance from point A to point B is some set amount, and I need to travel that distance. So I want something that’s safest per distance.

On that basis you’d go everywhere by scheduled airline.

The point is that you have to compare like with like. Walking is a mode of transport that is used by the majority of people for relatively very short journeys. Cars are used for relatively much longer ones.

You’d normally consider the safety of an activity on the basis of your chances of surviving doing it so it makes no sense to compare transportation safety on a per mile basis when people undertake dramatically shorter journeys on foot than in a car.

No matter how you want to argue it you stand a vastly higher chance of dying in a car than being killed walking. (Around 7.5 times in the US in 2008 See Here)

[Chronos]

No matter how you want to argue it you stand a vastly higher chance of dying in a car than being killed walking. (Around 7.5 times in the US in 2008 See Here)

Sure, but why is that relevant to me? What decision could I be making where, in order for it to be an informed decision, I would have to know that?

[kapntoad]

Missed a post, duplicated it. Beg pardon.

[kapntoad]

@Irishman

Chronos said:

It’s pretty close to 1:1, but that doesn’t tell the whole story, either. Basically, it spends most of the re-entry falling, to build up airspeed, then uses that airspeed to swoop closer to horizontal right at the very end so it can land.

That doesn’t sound right. Ionizer has it correct, the Shuttle spends the entire reentry trying to lose speed. That’s why there are those giant “S” curves as part of the glide path. It does have a steep glide path. The training airplane they use to practice is a converted jetliner where they throw the engines in reverse.

That’s what I thought too, but I checked NASA to be sure. They spend most of the landing slowing down but drop the nose to increase velocity and rate of descent the last few miles, then pull up to land.

http://www.nasa.gov/mission_pages/shuttle/launch/landing101.html

[billfish678]

I wonder how dangerous it would be to walk to the moon and back?

[qpw3141]

@Chronos

Sure, but why is that relevant to me?

I didn’t say it was relevant to your decision making.

Most intelligent people don’t decide a journey method by checking safety statistics.

I was just griping about deriving a headline from figures that, in terms of human usage habits, do not compare like with like.

[Lumpy]

Maybe rather than per mile or journey distance, another standard of comparison might be time spent in transit? For example is an hour in a commercial airliner more or less safe than an hour in a car on the freeway?

[scr4]

@qpw3141

The only sensible way to gauge such a figure is to base your calculations on typical journey lengths. If you want to assess how safe an activity is you want to know what you chances of survival are as you perform the activity.

Do you mean fatalities per trip?

What if you wanted to compare the risk of different ways to go from Boston to NYC (e.g. driving vs. flying vs. train)? Or different ways to get to work (e.g. driving vs. bus vs. walking)? With the “fatalities per passenger-mile” number, these would be a simple. But it’s impossible to compare the risks using the “fatalities per trip” number, unless you also know the average trip distance for each method.

[qpw3141]

@scr4

@qpw3141

The only sensible way to gauge such a figure is to base your calculations on typical journey lengths. If you want to assess how safe an activity is you want to know what you chances of survival are as you perform the activity.

Do you mean fatalities per trip?

It’s one way but not always easy (or realistic) to do.

What if you wanted to compare the risk of different ways to go from Boston to NYC (e.g. driving vs. flying vs. train)? Or different ways to get to work (e.g. driving vs. bus vs. walking)? With the “fatalities per passenger-mile” number, these would be a simple. But it’s impossible to compare the risks using the “fatalities per trip” number, unless you also know the average trip distance for each method.

This is rather the point. There is no way of sensibly comparing two modes of transport unless they are used for making the same type of trips. So you could compare air and sea for transatlantic crossings and car and motorcycle for road journeys but comparing two forms of transport that tend to be used for fundamentally different types of journeys and coming up with a headline figure is ludicrous.

In case anyone is still having difficulty with this let’s use a reductio ad absurdum:

Consider a entrepreneur sets up a business selling round trips to “See the Ice world of Neptune”. Unfortunately, every one of the ships he sends burns up in the Earth’s atmosphere on return. So that’s one fatality every (approx) 5 billion miles. So, according to those who believe that fatalities per mile is a sensible way of measuring the safety of a transportation system he could, despite the fact that no one has ever survived such a trip, legitimately claim: "The safest way to travel - over 90 times less fatalities per mile than traveling by car.