Advice from Liberty Mutual about tornadoes

[Chris McBee]

I ran across an article on Yahoo News today, talking about home insurance and how to prepare oneself for natural disasters. Under the section about tornado preparedness, there is a subheading about "what to do if driving." One of their suggestions reads as follows: "If possible, find a highway overpass. Get under the bridge and wedge yourself between or behind the concrete pilings."

With all the evidence against the safety of this, why is a huge insurance conglomerate like Liberty Mutual still suggesting it?

Link to the article: http://realestate.yahoo.com/loans/home-insurance/Preparing_for_a_tornado.html;_ylt=AgNR1l_P2FLyWkzWHIq_sHjo7Zx4

 

[Jason Foster]

Outside the chase community, this is still a very common piece of advise. I see it all the time.

I can't wait till there is an injury or death of one of their customers and they try to refuse to pay....of course, we'd rather that not happen.

Perhaps a letter to the company would change that.

 

[Mark Holmes]

Any time I give a presentation at work or school on severe weather, I always address this issue and tell the audience to spread the word to their family and friends. This bad advice has been propagated for way too long!

 

[John Wetter]

It is really unfortunate. I'd suggest contacting Liberty Mutual regarding this. I filled out the form and I'd urge others to do the same:

http://www.libertymutualgroup.com/o...name=LMGroup/Views/LMG&ft=1&fid=1138364707731

 

[Tyler Allison]

I sent in a complaint too. That's just dumb. The person who wrote it was probably some low level desk jockey and nobody thought to check the advice since it all "sounds good".

 

[Chad Cowan]

Just got this email:

Dear Mr. Cowan,
Thank you for your email about our tornado safety article on Yahoo! Real Estate. After further review of our tip to take shelter under a bridge, we acknowledge that this is not accurate advice. Bridges can indeed serve as a wind tunnel and could, in fact, make a situation more perilous. We have removed that tip from our article and the tornado safety page on our website.

http://realestate.yahoo.com/loans/home-insurance/Preparing_for_a_tornado.html;_ylt=AgNR1l_P2FLyWkzWHIq_sHjo7Zx4

Thank you again for bringing this to our attention.

Sincerely,

Glenn Greenberg
Senior Public Relations Consultant
Liberty Mutual Group/Boston

 

[rdale]

Good work Chad! Now if we could get this out of the public's eye too so easily...

 

[tom hanlon]

Prove that it is not safe

You know I understand the argument that it is a wind focus. so the bridge in general focuses the wind. so I would not want to stand in the middle of the road under the bridge.

But...
You look up under the eaves of the bridge. There are some serious nooks and crannies. You can not tell me that nestled in a 4 foot deep box, with a 3 foot height and 5 to 3 feet across. You can not really be saying that this is a dangerous and more windy place to be.

Not to mention that I often see that I can wedge my self in there pretty good. when the wind starts to blow, I would like to be wedged.

I think the theory that it is not safe makes some drastic model revisions and simplifies significantly what I know about bridges. I think it assumes a smooth surface and a generalized bridge.

Until I see the wind tunnel experiment with a real bridge with all the "structure" that comes together under the roadbed at the top of that embankment I am going up there.

Mythbusters has to proof otherwise.

Now, given a hundred people trying to squeeze into the safety zone of perhaps 15 person carrying capacity for bridge size. Too many people would be a bad thing.

I need to see the experiment. It seems to me given similar structures under flowing water, they accumulate debris, at the edges implying low flow. They get scoured in the middle, accumulate sediment at the edge. So stay out of the middle, get to the edge.

I just have to call theoretical BS, on this one. I mean all the homeless sleep up there because it is sheltered, less windy. The theorist see suction, but I see eddies and relief in the nooks and crannies, and suction in the middle.

If I open up a can of soup, and the wind blows across the top of the can, is it windier in the bottom of the can? I see the space between the cap of the last abuttment and the steel or concrete girders as just such a place.

Know if you open up the can at both ends and funnel wind through the can, then it is a windier place. This is analogous to the bridge as a whole.

The closed can is analogous to the spaces under the girder.

If I have to mythbust this one with my life, I will.

Given a culvert or some other feature I would go there first of course.

Now mobs of people heading for bridges is not a good thing, neither are mobs of people dodging tornadoes in cars. But as individual stormchasers we dodge tornadoes with our cars all the time.

So advice for the masses is one thing, advice for an individual is another.

--
Tom Hanlon

 

[Jeff Snyder]

You know I understand the argument that it is a wind focus. so the bridge in general focuses the wind. so I would not want to stand in the middle of the road under the bridge.

But...
You look up under the eaves of the bridge. There are some serious nooks and crannies. You can not tell me that nestled in a 4 foot deep box, with a 3 foot height and 5 to 3 feet across. You can not really be saying that this is a dangerous and more windy place to be.

Tom Hanlon

There are a lot of bridges that don't have any of the so-called "nooks and crannies". Many are just wedges, with nothing to hold on to or put your body "in". In such cases, you're just at the mercy of the wind, many times when you could just have driven safely away instead. Sure, there ARE some bridges that would provide adequate shelter in an emergency situation, but I can't imagine that Joe Q. Public would be able to know if any particular bridge is "good" or not. It's hard enough the way it is to get simple safety messages out there (e.g. get out of mobile homes, etc), so it's probably best to use the blanket statement "overpasses are NOT an adequate form of shelter!". Anything more than that would cause further confusion and potential for deaths and injuries.

FWIW, in the realm of severe weather preparedness, I'm not sure you can separate out the message you give to an individual vs. the message you give to the populace. Sure, any one person can shimmy up a bridge embankment and find a nook or cranny if the bridge has one, but I don't think you'll see many on here saying that it's a good course of action... Many of us on Stormtrack are involved, in one way or another, in the spotter and general public education realm. As such, with evidence certainly on our sides, it's best to discourage the use of any and all overpasses when one is seeking shelter from a storm. Of course, this even neglects problems with traffic (people block the highways to get out of their vehicles). Most of the time, people would be better off just driving away from the tornado instead of making for a very hazardous roadside or in-road traffic threat by abandoning vehicles to head up an overpass. I'm sure some homeless folks can sleep just fine up there in light-moderate winds, but 20 mph winds are drastically different than 120-140-160+ mph winds.

 

[Jason Boggs]

Tom, I'm not sure that a bridge wouldn't be a last resort in an emergency situation. Obviously it depends a lot on the bridge construction and intensity of the tornado.

What really gets me on the whole ordeal of using bridges as shelters is this. Eventually, it will lead to roads becoming clogged for others who decide not to use the bridge as shelters. In my eyes, people that use bridges as shelters are only hindering others in their decision making process. Here is a good read about using bridges as shelters in tornadic situations.

http://www.srh.noaa.gov/oun/papers/overpass.html

 

[tom hanlon]

Tom, I'm not sure that a bridge wouldn't be a last resort in an emergency situation. Obviously it depends a lot on the bridge construction and intensity of the tornado.

What really gets me on the whole ordeal of using bridges as shelters is this. Eventually, it will lead to roads becoming clogged for others who decide not to use the bridge as shelters. In my eyes, people that use bridges as shelters are only hindering others in their decision making process. Here is a good read about using bridges as shelters in tornadic situations.

http://www.srh.noaa.gov/oun/papers/overpass.html

Thanks for the article. That is the type of science I was looking for.

Last resort situation I would have to look around and see what I had available that I could get to in 20 seconds.

I trust my judgment rather than any simplified rules. Some of those bridges in that document, well they would certainly not be an option. Often there are drainage structures near a bridge that might be an option.

My point is largely that simplistic generalizations are what the general public might need. But simplistic generalizations are not accurate representations of the details .

--
Tom

 

[Michael Towers]

What really gets me on the whole ordeal of using bridges as shelters is this. Eventually, it will lead to roads becoming clogged for others who decide not to use the bridge as shelters. In my eyes, people that use bridges as shelters are only hindering others in their decision making process.

The traffic issue is one I know personally, nothing like almost getting caught in a tornado traffic jam all because people sought shelter under a bridge. I started filming Quinter #2 in the eastbound lanes of I-70 just west of an overpass; as it became apparent the track of the tornado threatened my location I glanced ahead of me saw the underpass getting blocked with vehicles! I’d only been filming for about 2 minutes and when I arrived the lanes were wide open but while I was filming some of the traffic that passed me decided to park under the bridge and threatened to block my passage. When I started filming I felt comfortable thinking I had the option to move if necessary but it never occurred to me that my escape route could get blocked by people thinking the bridge would make safe refuge. Call that one a failure in situational awareness, one I’ll never make again. The tornado was still over 2 miles away and could easily be evaded by simply continuing down the highway but instead people were lining up under the bridge. I was incredulous that with a tornado still so far away and easy to avoid that people would stop to take “shelter†in the seeming path of destruction! Thankfully a few cars moved onward and as I passed the remaining car I motioned for them to move along also and they did, following me out from under the bridge and down the highway to safety.

But the scene repeated itself minutes later, by this time I was safely situated and watching the tornado re-intensify as it approached the highway. Trucks were sitting under the bridge and would have been at the mercy of the tornado had they stayed and been in the tornado’s path. Fortunately for them they never realized that encounter; for whatever reason the truck in the right lane pulled out seconds before the tornado crossed behind the bridge. Perhaps the truckers behind him told him over the CB to move his ass or maybe he just felt like a sitting duck and moved. Regardless his motivation, nobody in the eastbound lanes was hit but one vehicle in the westbound lanes wasn’t so fortunate. Here’s a video still of the trucks moving out just before the tornado crosses, I can only wonder if the taillights seen in the opposite lanes belong to the car that got hit:



Personally, if I’m ever in a situation where I even consider sheltering under a bridge then I messed up big time. Even in the case of Quinter, if the passage under the bridge had been completely blocked I still had enough time to reverse down the highway. If no escape option existed and I was stuck by a bridge then it would depend on the type of bridge; if it had girders I probably would opt for there versus being exposed in the open. Ditch or bridge? Pick your poison. One thing for sure is I would not be waiting it out in my car.

 

[Steve Dedman]

If I am not mistaken, a number of people were killed under this overpass (Shields Ave. over I-35, Moore OK) on 5/3/1999. No shelter AT ALL:

Since not all types of overpasses are safe, you can't recommend getting under ANY overpasses because 1) in the stress of running for your life, the type of higher thought process needed to determine if an overpass is safe or not isn't always happening, and 2) you can't expect the general public to know which ones are safe and which ones aren't. Always better to err on the side of prudence.

A bit off topic, but I don't know if anyone has noticed that on google maps, if you zoom to the 2-mile scale sat image, you can clearly see the damage path across Moore and SE OKC.

 

[Sarah Glenn]

If I am not mistaken, a number of people were killed under this overpass (Shields Ave. over I-35, Moore OK) on 5/3/1999. No shelter AT ALL:

I actually think this photo is of the new overpass for Shields Ave. that was completed sometime in the last two years. It's a new, very elaborate interchange now. I imagine THE overpass looked quite a bit more like the others on I-35.

 

[Jared Thompson]

Found this link from the OKC national weather service. It show that overpass with pictures from right after it happened. It also is a slide show about over pass saftey. Thought it was intresting. http://www.srh.noaa.gov/oun/papers/overpass.html