Motorway barriers

The Doktor

testicle wrote:

I've seen this ****e spouted by bikers before. I still have to see any legislation from any EU country making them illegal. The EU itself can't make anything illegal, so that's part of your theory thrown out the window.

http://www.bbc.co.uk/dna/actionnetwork/F?thread=3327718

The Doktor

There are little or no stats on this. However studies have been done on motorcycle collisions with various types of barriers. The main cause of injuries is the posts stuck in the ground. There are various types of posts (different shapes) and we use the most dangerous type.
Research in California, France and Germany has indicated that the usual accident scenario involving a motorcyclist with a vehicle restraint is that the rider initially loses control and falls from the machine sliding into the barrier or safety fence at a shallow angle. Where safety fence with exposed posts is employed, the greater forward speed of a rider leads to a collision with the post with serious and often fatal consequences. Extremities are readily amputated and major internal injuries caused. A similar collision with a featureless concrete barrier or an additional lower beam which covers the posts, results in a lower sideways impact with the momentum of the rider scrubbed off by contact with the barrier and road surface. If the rider is wearing adequate protective clothing, injuries should be minimised.

As regards the posts used, there are different shaped ones. Some were found to cause less injury. However these were more expensive. In ireland, we use the most dangerous type on the rope barriers.

With Wire rope type barriers they have more post exposed than any other type, so they are going to do a lot more damage to a rider who hits them
Also there have been studies which shows that in an upright collision with a wire rope barrier the rider is actually directed into the posts. It was found that even in a low speed collision with the barrier (60kph) the rider would get their legs caught in the rope, be then directed to the posts, and thrown over the barrier causing serious and non survivable injuries.
In many European countries they are now starting to use "motorcycle friendly" barriers, which are like the usual armco, but have an added lower barrier to stop the rider hitting the posts. Also in norway, denmark and holland the wire rope barriers have been banned.

impr0v

There's a long way between "prominent MEPs have now suggested a ban in the European Union" and an actual ban.

Armco barriers without an extra low beam aren't much safer to bikers than the rope construction. Afaik in Ireland there aren't any low beams fitted, though I'm open to being proved wrong on this. Essentially situations where a biker comes into contact with the barrier at knee-hip height while in an upright situation are few and far between, the majority of contacts are when the biker is on the ground and sliding, and the poles are the part of the barrier that does the damage. This is the case with both armco and the wire-rope construction.

The justification for the wire rope isn't purely fiscal, it is quicker to erect making it more suited to a retrofit on live carriageways, and has improved energy absorption capabilities, thereby reducing the rebound of vehicles back into traffic.

EDIT: posted before the doktor posted the above.

testicle

The Doktor wrote:

http://www.bbc.co.uk/dna/actionnetwork/F?thread=3327718

Norway is not in the EU.

The Doktor

testicle wrote:

Norway is not in the EU.

Read the article... Denmark has removed all of theirs, and Holland has banned their use.

_Kaiser_

The Doktor wrote:

As regards the posts used, there are different shaped ones. Some were found to cause less injury. However these were more expensive. In ireland, we use the most dangerous type on the rope barriers.

In other words, the cheapest I'll bet :rolleyes:

The Doktor

Kaiser2000 wrote:

In other words, the cheapest I'll bet :rolleyes:

emmm... yeah:D

_Kaiser_

The Doktor wrote:

emmm... yeah:D

I meant moreso how if it's cheap and "ah it'll be grand" then you can be sure it's the option we'll get every time :mad:

impr0v

That's neither necessarily fair nor true.

Since you've concluded that the currently used poles, which have a something approximating to an I-shaped cross section, are cheaper than the poles with a circular or elliptical cross section, let's say for arguments sake that they are 15% cheaper. It may be more or less, but the 15% will serve as an approximation.

In order to justify the use of the more expensive poles in purely financial terms, and for all we know there may be no suppliers in the country, or there are Irish (i.e. modified British) standards issues with them, you'd have to show the following:

That the small percentage, of the small percentage (of overall traffic) of bikers in this country, who come off their bikes and slide into such barriers (on the small percentage of the overall network that these barriers are utilised on) at speeds and angles of entry which won't kill them, regardless of what they hit, will suffer injuries from colliding with the circular poles that are less severe than those that would have been inflicted by the I shaped poles, by a quantifiable figure X.

X can be calculated from the sum of the difference in the following factors between the two injury severity levels: insurance claim costs; medical costs; loss of productivity over the rest of his/her life as a result of the injury; the cost of long term care/rehabilitation; and perhaps more criteria.

While the barriers have been installed on a small percentage of the overall road network, the lengths they have been installed on are not insignificant, and comprise large sections of many of the major interurbans. In other words, the 15% difference would amount to a significant sum. Would it be greater or less than X?

Do you think that there are enough accidents where the type of poles would make a real difference to injuries sustained to justify the extra expense? Personally, I don't have the data above to show it, but I seriously doubt it.

The equation is further complicated if you attempt to include other elements of the roads program where the money would have to come from to make up the difference, stretches of road where car (the vast majority of the road-using vehicles) accidents occur with almost predictable frequency and the funding for which may already be precarious.

My point is that it's not necessarily an outbreak of 'it'll do' thinking, it's just as likely to be the result of cold calculation and risk assessment.

EDIT: typo

The Doktor

Improv, I know what yer sayin, and lets be honest money is a big factor in why they use these barriers. But the reasons behind the banning in a few countries has a lot to do with cost. Im sure the politicians went on about how its to save lives, but what has been found with wire rope barriers is that they are cheap to install but with the cost of maintenance added, the total costs are actually comparable to installing motorcyclist friendly barriers in the first place..
I would say the reason the wire barriers are in is because a few years ago there was a row over motorways having no barriers, and these ones were a quick solution... but in the end they will cost us just as much...

Victor

whosedaddy? wrote:

I'm not a fan of those unside-down y shaped concrete barriers.

Jersey Barriers?

http://images.google.ie/images?hl=en&q=Jersey+Barriers&btnG=Search+Images&gbv=2