"Jersey Barriers"

[Dudesky]

I'm watching a show called Crash Science, and they're talking about concrete median barriers. Wow I had no idea there was so much engineering that goes in them. So I looked it up on the net, some of you may find this interesting . .

http://www.tfhrc.gov/pubrds/marapr00/concrete.htm

For the more common shallow-angle hits, the NJ-shape is intended to minimize sheet metal damage by allowing the vehicle tires to ride up on the lower sloped face . . . It is only necessary to lift the vehicle enough to reduce the friction between the tires and the paved surface. This aides in banking and redirecting the vehicle. If the vehicle is lifted too high into the air, it may yaw, pitch, or roll, which can cause the vehicle to roll over when the wheels come in contact with the ground again.

[Numark318i]

heh nice.

i watch a show like the one you are talking about.

Its crazy how much testing goes into this sort of stuff. I mean im happy they do it, im sure they have saved many lives by doing so.

[celsdogg]

that would be an excellent job, engineering and then testing the barriers.

the NJ turnpike authority is all about making barriers. cool.

[doughboyea]

Those Jersey barriers only work so well when it's a car, imagine a large SUV or semi... forget about it, the barrier becomes a ramp. Yet they do seriously slow down the vehicle, but once it breaks through, it's a whole other story. I know the article says otherwise, but, if you travel on Rt. 287 southbound, there's an impact crater from a semi that busted through one barrier right around the Morristown exit ramps.


Notice something else though, the NJTA uses the metric system, it's a pain in the ass when nobody else uses it in NJ.

Dough

[Dudesky]

You're the engineer, so I won't question this. But I did see footage of them testing the barriers on semi's and straight trucks as well. And they did say that the barriers need to be maintained; any defects, roughness, or cracks/breaks on the concrete can cause them to not work as predicted

[mullethunter3]

Sweet! Actually, in Dynamics on Thursday, we got to watch all the crash videos form a doctorate presentation on crash engineering. Our chancellor did his thesis on it.

I haven't watched your video yet, but if it has a sloped concrete barrier in it... the car can go flying for about 100 feet and get ~50 feet of air. Sweet!

[TerryY]

Sometimes these things meet a lot of resistance before they are implemented.

At the junction of the original I-15 and I-10 in San Bernadino the ramp to LA (coming from Las Vegas) had at least one serious crash a weekend and several fatals a month. This is set in the pre airbag and seat belt law era by the way.

The guard rail end had some sort of renewable barrier for the convenience of the clean up crew but it didn't do much for the crash victims.

The inventor of the sand and water filled compression barrels had been trying unsuccessfully for a year or so to get the state of California to try them somewhere but they refused to pay for anything that sounded that stupid.

After a particularly bad weekend on that ramp, he offered to put a set up for free and even took out an insurance policy to assume liability if it failed. So for free someone said OK.

Upon finishing the installation, the inventor and the dude from the state highway department are walking back to the truck when they are deluged by sand and water falling from the sky!

Guy climbs out of the car that was going at least 70 when he hit the drums and asks "what the hell was that doing in my way?" (That was paraphrased to spare the innocent from profanity) Then his wife and 4 kids climb out of the car - all uninjured other than minor bruises and cuts. At that speed of impact it would have been 6 fatalities an hour earlier.

Funny thing but his barrier became a permanent fixture on that spot that day and he couldn't make enough of them fast enough to keep up with demand..