Life expectancy of a pedestrian on a motorway

http://www.roadsafe.com/magazine/win.../page_146.html

In fact, research has shown that the life expectancy of a pedestrian on a motorway is just eight minutes.

I've been told this "scientific fact" numerous times by friends or relatives (with some variations in the life expectancy, from 8 to 30 minutes), but I've been so far unable to find the origin of this statistic.

I know it's dangerous for a pedestrian to stay on the hard shoulder of the highway. In some countries (Spain, Italy...) reflective safety jackets are even compulsory for that reason.
But it's hard to believe that it reduces so much the life expectancy ! And how do they calculate this ?

Does anyone have any idea of the origin of this stat ?

[matches]

Originally Posted by alsachti

http://www.roadsafe.com/magazine/win.../page_146.html



I've been told this "scientific fact" numerous times by friends or relatives (with some variations in the life expectancy, from 8 to 30 minutes), but I've been so far unable to find the origin of this statistic.

I know it's dangerous for a pedestrian to stay on the hard shoulder of the highway. In some countries (Spain, Italy...) reflective safety jackets are even compulsory for that reason.
But it's hard to believe that it reduces so much the life expectancy ! And how do they calculate this ?

Does anyone have any idea of the origin of this stat ?

I don't know the origin, but i would theorize, presuming it is not made from whole cloth, that you would arrive at a number by looking at pedestrian fatalities on motorways, and determine how long they had been on the road prior to being hit.

Persumably most people don't spend a great deal of time, simply walking back and forth across motorways, so it is safe to say the persons in question should only be those people who are in the process of crossing the street.

given that, you simply average out the length of time people were on the motor way before getting hit. That gives you the average life expectancy of someone who is going to get hit. You then take the ammount of time that it takes to cross the motorway without getting hit. You then take the larger number and that is your answer.

If it takes less time to cross the motor way than it takes to get hit, you can assume that if you are on the motorway you are likely to get hit within that period of time. If it takes longer to get across the motorway than to get hit (on average) then you would presume that the time it takes to cross the freeway is the maximum ammount of time one can spend on the freeway without getting hit. Given that the numbers offered are 8 minutes and 30 minutes, and one would presume you could walk across a motor way in far less time, one would presume that the average of hits was the larger number.

As such it is safe to say, that if you spend more time than necessary to cross a motorway you are likely to get hit within that time frame.

[Hepcat]

I went to Google and did a bit of a search looking for evidence to back up that claim, and could not find any. That does not mean it is false, though. It just means I could not find anything.

[Darth Credence]

I would say this is a bogus number, whether made up entirely or just due to truly bad statistics.
Since life expectancy is how old one is expected to live, then for the statistic to be true, almost every being that crosses a road must be younger than 30 minutes old. So for the actual definition it is clearly out.
They must therefore be going for a different definition. The only other one that makes sense is life expectancy from the current moment. That doesn't hold up, either. If 99 out of every 100 people who cross the road are killed in a second, and the other one makes it safely and lives another 50 years, then life expectancy is about 6 months.
If this was a true statistic, it would have to be phrased in a way similar to IDL50, where the time is the time in which have of those exposed to the hazard are killed. If it was said that the IDL50 level for crossing a freeway was 8 minutes, then I would not have any initial issues with the statement.

[Andrew of Ware]

Reading the article in the OP it seems to me that they are talking about a British motorway as the sentence before mentions 'hard shoulders' and the website is clearly British.

When the recovery is taking place on the hard shoulder of the motorway, the environment is one where the risk of serious injury or death is very high. In fact, research has shown that the life expectancy of a pedestrian on a motorway is just eight minutes.

In addition, if they are talking about pedestrians on the actual carriageway of the motorway, not even the hard shoulder, then maybe eight minutes could be creditable, but it depends what the pedestrian was doing on the motorway and where exactly s/he was.

From the 'About Us' page on the website:

RoadSafe is a road safety partnership of leading companies in the motor and transport Industries in Britain, the Government and road safety professionals. It aims to reduce deaths and injuries caused by road accidents and promote safer driving.

[Jay Tea]

If swans can dodge traffic so easily then i'm sure humans can do the same

Reading that article, it says 'swans cannot take off from solid ground' - is that true?

[Hans Off]

Originally Posted by Jay Tea

Reading that article, it says 'swans cannot take off from solid ground' - is that true?

You know that is one "fact" I have always wondered about but have never bothered to look into!

My insticts tell me it is correct due to the way they get airbourne...I could be wrong though.

[Stoneage Dinosaur]

Originally Posted by Jay Tea

Reading that article, it says 'swans cannot take off from solid ground' - is that true?

I have heard that, but this site claims that Tundra Swans can take off from both land and water. Maybe it only applies to Mute Swans?

[JessBoo]

Originally Posted by Jay Tea

Reading that article, it says 'swans cannot take off from solid ground' - is that true?

I think (I could be totally wrong but there's something at the back of my mind about it) it has something to do with their wings being so big- if they are on ground then their wings won't go far down enough, whereas in water the tips of the wings can hit the water and go a bit beneath it. They're very splashy when they take off.

The niggly thing in my mind about this appears to be linked to the Really Really Wild Show, so if I'm wrong, blame Michaela Strachan. or Terry Nutkins. But not the other bloke, cos he lives nearby and might come after me...

EDIT:

Behaviour: The black swan makes a trumpet-like call when it moves from one feeding ground to another. It is difficult for swans to take off as they need a long expanse of water from which to become airborne. Once they are off the ground, they have a strong and graceful flight.

from http://www.bluemts.com.au/reptilepar...?catID=1&ID=15

And thinking about it, I am probably wrong because their wings don't go straight up and down, to they? They arc as they take off. Hmm.

[Hans Off]

I think it is about the amount of initial lift they can generate that requires some forward movement to help out.

Swans cant really waddle that fast on land.

I suppose with a strong enough headwind a swan would hust be able to open its wings and go.

That's why hummingbirds are not as big as swans.

But it would be cool!

As I understood the "statistic", it was more :

"a pedestrian staying on a motorway (normally, on the 'hard shoulder'), has, on average, just x minutes to live"

than

"a pedestrian crossing the motorway has, on average, just x minutes to live"

The only way this fact could be verified is if they had cameras on the road and actually went back after each death and reviewed the tape to figure out the time.

The could only make sense if they only examined the deaths and then they could figure out that the average person that died was only on the side of the road for 8 minutes. How could they otherwise tell if someone broke down and waiting for 30 minutes until someone came and picked them up or if they had to stop for a "call of nature" and then got back in their car and left. I think what they probably meant was "The pedestrians killed on the road were only on the road an average of 8 minutes before they were struck by a car and killed."

If you just looked at the statement: "In fact, research has shown that the life expectancy of a pedestrian on a motorway is just eight minutes." the only way that could be true is if every single pedestrian died. If only one lived that alone would throw off the 8 minute number by quite a bit.

Bunion

[Deepfrydegg]

I think the number is just made up.

After all, how many policemen, firemen, tow-truck operators or even hitchhikers walk on the motorway and survive?
Answer: Most of them, and for much longer than 8 minutes.

Of course, I am putting anyone who is not in a motor vehicle for a while in that category of "pedestrian." If your auto breaks down or gets a flat tire, you have to walk to the call box to summon help. That makes you a pedestrian.

Caveat-Many roads have different sorts of shoulders and emergency lanes. Some are more dangerous than others.

I think they may be only counting fatalitites. Something along the lines of "All the people who died on the highway were killed in an average of X minutes." In which case this wouldn't be the life expectancy of a pedestrian. It should read something like, "If you are going to die walking on the highway, then it most likely to happen in the first X minutes."