The case for concrete median road barriers

Typewriter

I created this thread to stop the off topic posting involving this subject in the other threads.

(go for it lads):)

http://www.cca.org.nz/pdf/barrieropinion.pdf

Celtic Warrior

Here's a couple of pics from a Belgium motorway with concrete barrier. The belgiums use mostly this sort of barrier.

Note also the motorway lighting - The vast majority of the motorways in Belgium have lighting which makes driving alot easier but its a shocking waste of the megawatts!

KevR

Just a couple of posts I made in other threads:

KevR wrote: »

I think the idea behind concrete barriers is that in an impact from a shallow angle the step (wider at the bottom) will cause the wheel of the cars to bounce off the barrier with little damage to the body of the car (because the barrier is narrower higher up).

From a more acute angle the nose of the vehicle will start to slide up the barrier; the wheels will then impact of the lower part of the barrier and the car's suspension will be able to absorb a lot of the impact.

A simple yet great idea.

Good info on it here: http://www.concretebarrier.org.uk/

KevR wrote: »

I emailed the NRA last week asking what their reasons were for deciding to go with a metal barrier on the Athlone-Ballinasloe scheme and if they are planning on using metal for Galway-Ballinasloe like I suspect. Still waiting to hear back but will post in the M6 thread as soon as I do.

I don't understand why they would use metal at all. It's not as safe, it has a life span of only 20 years (as opposed to 50 years for concrete), and requires a good deal more maintainence. It might cost less initially but over a 50 year period will cost a lot more.

Gone a bit off-topic there, sorry.

BluntGuy wrote: »

I e-mailed them in December and didn't get a response.
I e-mailed them in March and didn't get a response.

It's a lucky dip job I'm afraid... don't expect a reply if your question is too testing.

I actually emailed them about an N6 issue and they got back to me within 24hrs telling me that I should have contacted Galway County Council in that instance. Fair enough I suppose but I replied asking about the steel-vs-concrete barrier and have heard nothing back in a week. Got a quick response when they were telling me to contact elsewhere but when I had an actual question for them......

loyatemu

on the negative side - they are very bad for wildlife. The new interurbans are the equivalent of building a wall across large parts of the country - apart from the extra roadkill caused by animals being unable to cross, they seperate different populations of species reducing the potential for interbreeding.

Amtmann

loyatemu wrote: »

on the negative side - they are very bad for wildlife. The new interurbans are the equivalent of building a wall across large parts of the country - apart from the extra roadkill caused by animals being unable to cross, they seperate different populations of species reducing the potential for interbreeding.

In theory this is mitigated by incorporating mammal passes (essentially, tunnels) beneath the motorway along established tracks. I have seen several of these on the Mitchelstown to Fermoy stretch. Unfortunately it takes wildlife time to become comfortable using these. I saw at least 11 individual badgers dead on the M8 between Cullahill and Horse and Jockey last spring alone.

Celtic Warrior

Maybe building Ecoducts in areas rich in wildlife is an option? If the underpasses don't work out.

See link: http://en.wikipedia.org/wiki/Wildlife_crossing

Now I'm not saying put them everywhere but I'm sure there are areas on the M8 for example where they would suit. Even look at the N/M11

Tech3

Celtic Warrior wrote: »

Maybe building Ecoducts in areas rich in wildlife is an option? If the underpasses don't work out.

See link: http://en.wikipedia.org/wiki/Wildlife_crossing

Now I'm not saying put them everywhere but I'm sure there are areas on the M8 for example where they would suit. Even look at the N/M11

Would rather see cut and cover tunnels IMO. Cant ever see that happening in this country

Road-Hog

Just to let you know, mammal underpasses for badgers, otters etc are an integral part of every major road project over the last 10 years. During the perparation of the EIS the ecologists identify all badger, otter populations that will be affected by the route and appropriately sized and positioned underpasses are then incorporated into the final design

Amtmann

Ecologists are supposed to identify all badger setts, but sometimes they miss one. For instance, there was a huge sett across from my home in Tipperary before the Cashel-Mitchelstown scheme was built. Some old men from the area say it had been there since at least the 1930s. But it wasn't spotted by the contractors and their ecologists. I had to point it out to them. An artificial sett was constructed for the badgers, which were all trapped and relocated.

KevR

Saw an advert for that Garda Traffic Corps TV show - it mentioned something about them attending an accident where a vehicle broke through the central barrier and crossed over to the other carriageway.

I think the programme will be on Sunday night. In the advert it looked like a cable barrier - I'm certainly interested in seeing what happened, what sort of vehicle was involved, damage to the barrier....etc.

Carawaystick

There's loads of these wildlife overbridges on the A85 in France, with trees and all growing on them. And at least two bridges over rivers where the motorway reduces to a single lane each way. I guess this has something to do with fish not going under a long tunnel of dark or something.
It definitely seemed the most environmentally considerate of the Autoroutes in France I've driven on.

Celtic Warrior

I've seen ecoducts in practically all the countries on the continent.

Some of them are amazing. One time I thought I was driving into a forest! :eek:

Must try and get a few snaps!

Celtic Warrior

Here ye go! Here's a good example of a dutch Ecoduct built on the A50 motorway

IMG_3015.JPG

IMG_3014.JPG

Celtic Warrior

Here's a picture of a Belgian ecoduct on a motorway in the Ardennes. Sorry didn't get a great picture but you get the idea anyhow.