Dividing concrete walls on Highways

[obelix]

A while ago there was a discussion on the danger of concrete walls on Highways and specific danger to riders.

I posted this question to our national road safety council here in Luxembourg and got the following answer (truncated and translated):

...

As the traffic and the average speed notably increased in the past years so did the number of heavy accidents where vehicles passed over the separating barriers and into oncoming traffic. This became a major problem. The long time used steel rails couldn't cope with the load of a heavy impact. So they were replaced by concrete walls. On impact they keep the vehicle in lane in most cases even without major damage. Motorcycle riders are better protected as there is only a flat surface to slide on and the steel supports of guard rails that had sharp edges and caused so many severe injuries are completely eliminated.

......

After all they might be right. The danger is without doubt higher when you slide into upcoming traffic. :huh: Also the guard rail supports are indeed a high risk. Several thousand posts here were enveloped in a special foam and miles of secondary flat rails just above ground were installed in dangerous spots. Still the impact on poles and rails is a major risk. I posted a while ago some pics of a rider having hit a warning sign. I have several more pics in my collection showing deadly injuries on bikers, many of them having hit guard rail supports. Usually this results in a clean cut/tear off of the arm, leg or neck when you slide under a barrier or hit a support.

 

[johnny80s]

The problem with the concrete barriers, at least in the states, is that they are not that high. When you ar eon the bike the wall is at knee level and easy to fly over it.

 

[obelix]

Sure tis is a problem. Our walls are all about chest high. Even those plastic dividers filled with water are hip high.

I don't see the point in knee high barriers. What are they good for?

 

[Fred W]

The concrete barriers make you safer on your bike because you won't encounter as many flying cars or trucks crossing the median from the other side.

When you go "off-roading" toward the median on a bike you're pretty much screwed no matter what they put there...

 

[mattster31]

The only concrete wall I have come in contact with was at Shannonville (racetrack) <_< I would not want to meet one on a highway. I think you would just become a speedbump for the other cars.

 

[windchaser1942]

Sure tis is a problem. Our walls are all about chest high. Even those plastic dividers filled with water are hip high.I don't see the point in knee high barriers. What are they good for?

Permit me to be "facetious": so the driver in the on-coming lane can watch you crashin'. Also, there pretty good for "blinding on coming drivers" with your headlights. Since most people are mislead into thinking just because there is a wall...no need to dim the lights. In reality ....the walls are dividers or separators. Possible protection would be an afterthought!

For the bike rider you can put the "knee hi's" into the same category as railroad crossings that run at a 45 degree angle to the roadway centerline.

 

[obelix]

Our concrete dividers are now different from the US (as far as I remember them). They are composed by 2 about 5 feet high walls about 5 feet aparts. The space between them is filled with soil and dense plants grow on them so this solves the blinding problem quite well. Also the soil adds to the rigidity of the construction.

I suppose it's less dangerous to be trown back in the same lane where followers running at the same speed have already noticed your problem then to be ejected on upcoming traffic who will be completely surprised by your fast flight.

 

[Bustanut joker]

The concrete barriers make you safer on your bike because you won't encounter as many flying cars or trucks crossing the median from the other side.
When you go "off-roading" toward the median on a bike you're pretty much screwed no matter what they put there...

FUZZY BALLS!!! Good an ya Fred. Though in these litigious times folks are going to sue and or whine about anything.

Somebody ought to shut this down fast, as dumb asses, who feel the need to bitch, are gonna derail it anyway..

Yeah, I have a case of the ass today..

Ah Hell.. I bet somebody has a safer, proven method of keeping forty tons of uncontrolled 'large car' on the right side of the road

:jester:

 

[phobostx]

Here in Texas, TXDOT is going to guardrails made of multiple (4-6) strands of braided metal wire. It works relatively well at deflecting vehicles back into their side of the road but it looks like an "amputation device" for motorcyclists. I'd venture to guess a 60+ mph introduction and you'd look like you went through a food processor.

 

[johnny80s]

The concrete barriers make you safer on your bike because you won't encounter as many flying cars or trucks crossing the median from the other side.
When you go "off-roading" toward the median on a bike you're pretty much screwed no matter what they put there...

You got that right Fred.

 

[wfooshee]

Another thing about our concrete dividers is that they are not vertical, but spread out with a curve to a base that is wider than the wall. The designed effect is to catch the front wheel of the wayward vehicle and force the steering towards the wall, keeping the vehicle from bounding back out into traffic. On a bike it throws you over the wall, which is unfortunate if the wall is at the edge of one of those 130-foot high interchange ramps.

The best example I've found in my quick search is at 2:07 in this video. Watch the front wheel opposite the impact, and notice that it does steer towards the wall before the impact lifts the vehicle off the ground, and the vehicle's line after that is along the wall, rather than reflected off of it. Also, that wall has a fence over it which is not a barrier. It might be used to block oncoming headlights, or it might be just a catch fence for debris from the test. The only barrier is the low concrete part. That's what we deal with in the states.

For scale on a bike, here's a pic I took a while back for Tim's "Been everywhere" signs project. The rail is on the bridge over St. Andrew Bay here in north Florida. You can see how much "protection" a rider could expect from that. Although I think I'd rather hit that than armco.

 

[Fred W]

Yeah, that would be what they call a "Jersey Barrier" around here. But the ones they are building now on I93 are completely straight (vertical) and higher

 

[obelix]

I can't believe they installed WIRE STRANDS on top of the dividers. Anybody having basic notions of safety will tell you this is indeed a cutting device. Maybe they don't like the costs involved in long time recovery of bikers and prefer to draw a clean line.

Steel barriers are also dangerous regarding their supports. I found that it is now mandatory in many european countries that new or refurbished constructions in exposed areas are outfit with a secondary rail.

Many MC organisations have outfit the posts with so-called crash protectors, made of extruded foam. They are priced at less than 4 Euros apiece (less then 6$) but should be replaced from time to time as the foam decomposes from UV rays.

When looking this up all sources were sure that it's more dangerous to have someone slide over/under a barrier than have him bounce off.

Sorry wfooshee, can't look at the video for Youtube restrictions (says...not in YOUR country...)

Now this is what happens if a biker hits one of those clad poles:

.. and this is how the bike looks

In this case a 29 yo biker fell off the bike and hit many foam clad posts in a row. Had'nt it been for the protectors he'd be dead instead of "only" severely injured. But if there'd been a secondary rail instead of the posts I suppose he could have walked away.

 

[Thug]

We have many Wire Rope Barriers here and every motorcyclist who has hit them has died.... they are a fucking death trap for motorcyclists period!!!!!

Jersey barriers (Ours here are old but they are about 4 to 5')

And some modified W rails have panels under the guard to fill up the space so you don't crash into the posts!

There are some companies designing Motorcycle Friendly barriers but to date we as motorcyclists have not made a bigger enough deal about it and so therefore wont get any attention from those who can change things...We are after all our own worst enemies sometimes.

Wire Rope Barriers are the most dangerous for us out there bar none....they trap the rider and guide them into the steel posts causing fatal deceleration blunt trauma