Cats' Eyes/Road Studs

Amtmann

Just said I'd start a thread on these. I have a few questions which I hope Berty or Blunt might be able to answer.

Firstly, why are these sometimes installed right on the yellow line on some of our motorways, and just outside the same line on other motorways?

Secondly, can someone post a picture of the machine that installs the studs, and maybe describe the process while they're at it.

Carawaystick

And why are studs used now instead of cat-eyes?

Amtmann

I like to use "stud" as a verb, as it is easier to use than "cats's eyes" - e.g. "lining and studding has been completed" vs. "lining and cat's eye installation has been completed".

Less wordy...

KevR

I don't like when they are placed inside the lines. Prefer them to be on the line or on the outside of it. In lane 3 of the M50 it's particularly noticeable/annoying - the lanes seem narrow as it is and lane 3 (also possibly lane 1) are effectively narrowed further by the studs.

xabi

Don't the NRA have 'standard procedures' for road building, surely this should be covered somewhere - just another inconsistency in our road building.

X.

emfifty

i think most of the older schemes have studs on the line. it is possible they decided to move them inside the line for one of the following reasons; newer schemes have rumble strips on the inside and hard shoulder lines and/or they want to avoid replacing studs and then removing them to have the lines repainted.

Carawaystick

Furet wrote: »

I like to use "stud" as a verb, as it is easier to use than "cats's eyes" - e.g. "lining and studding has been completed" vs. "lining and cat's eye installation has been completed".

Less wordy...

but studs are a triangular reflector thingamajig while a cateye is self-cleaning when something drives over it (for a while, then it breaks)

Anyhow, isn't cat-eyeing the correct verbing

Germany, France and Spain don't use them, i was told in Germany it's to allow the snow ploughs, don't think snow'd be a big an issue in the other two places though.

Celtic Warrior

I've seen them use Led's in Holland on bad bends. There sort of sunk into the asphalt.

And as we all know led's have a long long lifespan

Never seen the traditional type used in Ireland on the continent though? anyone else seen them?

Carawaystick

I first saw leds in Antrim, on the A26, frightened the bejaysus out of me as I though it was twinkling of ice and I was doing about 65...(mph...as those boys haven't gone metric yet.) They are now on the N11 between the Tap and Beehive and on the N71 somewhere east of Clon.

I think they're distracting, and they keep catching my attention out of the corner of my eye out the side window.

There's some ( or were any how) on Dame Street in Dublin, at the pedestrian crossing outside the Olympia. they flash red when the red light is on. These are a good idea, the road is 4 lanes wide and if you're in the centre lanes it's awkward to look to either side. Especially if a bus or lorry is there blocking the view of the lights.


Anyway, To make a guess at the answer to why the studs are sometimes left and sometimes right of the line - usual irish AhSherTwillDo-ism. I'd say they are not on the line to allow easy repainting/rumbling maintenance. If they were outside the lane, they'd be hit by traffic less and last longer, I'd imagine.

Another guess thinking about it, the studs are "nailed" down on the surface, while cateyes are actually inserted into a hole in the surface and bedded in
I remember trying to pull a broken cateye out of the ground once as a smallie with less sense.

BluntGuy

Furet wrote: »

Just said I'd start a thread on these. I have a few questions which I hope Berty or Blunt might be able to answer.

I'm not an expert on the topic, but I can answer one of your questions.

Secondly, can someone post a picture of the machine that installs the studs, and maybe describe the process while they're at it.

Well I can give you a quick summary of the process:

Cavities in the asphalt are drilled out using hydraulic drilling machines. What these machines look like - I couldn't tell ya.

For installation of a specific stud, the alcoves in the casting base are filled with molten bitumen and allowed to cool.

You then fill the cavity in the asphalt with molten bitumen - placing the stud immediately on top of it. The stud is then adjusted so the molten bitumen rises from underneath the stud up the cavity sides. More bitumen is then added until the sides of the cavity are at road level. Obviously an engineer would go into more detail, I know only the basics.

I've heard this referred to as the "bed and grout method". There are other methods as well, but this is the one that's used on most road schemes as far as I know.

Unfortunately, I couldn't find any web links that give you more information on this.

Firstly, why are these sometimes installed right on the yellow line on some of our motorways, and just outside the same line on other motorways?

Now that is something I need to find out myself!

bushy...

Celtic Warrior wrote: »

I've seen them use Led's in Holland on bad bends. There sort of sunk into the asphalt.

And as we all know led's have a long long lifespan

They seem to do more for safety than any of the daft ideas .

"Over a three year period there were 22 recorded accidents, 2 of which involved loss of life, along with 6 causing serious injury and 14 others considered as minor."
In the first 2 years 2 months since the initial scheme introduction there were only 5 recorded accidents (all slight) of which none occured during darkness and only one in wet conditions.

"Accident frequency has reduced from 7.3 per yr to 2.3. Severity ratio has reduced from 36% to zero."

http://www.astucia.co.uk/Case-study-Norfolk-A143.aspx

Celtic Warrior wrote: »

Never seen the traditional type used in Ireland on the continent though? anyone else seen them?

Like everything no-one else wants , they end up here.

Rovi

Furet wrote: »

Secondly, can someone post a picture of the machine that installs the studs, and maybe describe the process while they're at it.

To hear is to obey:

https://www.youtube.com/watch?v=4MTqft1N58s

Amtmann

Good man Rovi. Thanks for that.

BluntGuy

Excellent video, perfectly demonstrates the "bed and grout method" I described earlier.

You can see him pouring in the molten bitumen into the cavity, place the stud etc.

murphaph

Rather than starting a new thread...
Does anyone know if there are any written maintenance standards for cats eyes? It is terribly disappointing to see long stretches of road with non functional cats eyes. I really noticed it last week on the R445 between Naas and Newbridge. The older surface has cats eyes but none of them reflect at all. Then there's a resurfaced section with new cats eyes all twinkling brightly. I mean if cats eyes are not going to be maintained then there's really no point installing them!

medoc

Also when they are maintained/replaced they should be of a good quality. About 6 weeks ago a 5km section on the N52 outside Kilcormac had new cats eyes installed. By now well over a quarter of the yellow ones have fallen out. Complete waste of money!

hi5

And the cats eyes that were ripped up by the snowplough's on the M9 back in 2010 were never replaced.
If they want to improve safety, then instead of average speed cameras maybe just maintain the markings?

annfield1978

Design Standard

http://www.transport.ie/upload/general/12971-TSM_CHAPTER_7-7.PDF

The quality of road studs varies widely unfortunately

chewed

Can cats' eyes get dirt on them (e.g. mud, tar, etc)?

hi5

chewed wrote: »

Can cats' eyes get dirt on them (e.g. mud, tar, etc)?

The old steel ones were self cleaning, they were mounted in flexible rubber, and when you drove over them little brushes cleaned the lenses.

murphaph

hi5 wrote: »

The old steel ones were self cleaning, they were mounted in flexible rubber, and when you drove over them little brushes cleaned the lenses.

They're the ones that are still supposed to be installed between driving lanes. They should only be using the nail on studs on the hard shoulder or on dual carriageways or motorways just beside the central reservation.

If you Google you quickly find that most UK roads authorities have minimum loss rates of cats eyes which trigger replacement. I couldn't find any Irish council with such information. I doubt it exists even internally but would love to be proven wrong.

cast_iron

The M4 has a shocking rate of failed cats eyes. They are not the old traditional type of "eyes", but actually reflectors. A good 30% failure rate at least. And the road is only a few years old.

A newer couple of roads i've driven on since seem to have gone back to the traditional "eye" type. Were the reflector types a failed experiment?
Is there no warranty with these from the road builders?

tonc76

The 1200 Series of the MCDRW has been updated recently and includes failure rates for road studs etc. It also gives initial performance requirements and guarantee periods. http://nrastandards.nra.ie/road-design-construction-standards/mcdrw/volume-1-nra-specification-for-road-works/series-1200-traffic-signs-and-road-markings

murphaph

tonc76 wrote: »

The 1200 Series of the MCDRW has been updated recently and includes failure rates for road studs etc. It also gives initial performance requirements and guarantee periods. http://nrastandards.nra.ie/road-design-construction-standards/mcdrw/volume-1-nra-specification-for-road-works/series-1200-traffic-signs-and-road-markings

Thanks for that. I see the minimum standards expected of contractors but I don't see anything about failure rates triggering replacement post guarantee period. Have I overlooked something?

It's certainly a start...something worth asking the Minister of Transport about. It's his job to make sure our roads are safe and if cats eyes are failing en masse and not being replaced (as is the case on many stretches of road) then it's something he needs to address with the NRA and local authorities.

They talk a good talk when it comes to road safety but all too often they concentrate on speeding and neglect "simple things" like maintenance of the road markings.

murphaph

cast_iron wrote: »

The M4 has a shocking rate of failed cats eyes. They are not the old traditional type of "eyes", but actually reflectors. A good 30% failure rate at least. And the road is only a few years old.

A newer couple of roads i've driven on since seem to have gone back to the traditional "eye" type. Were the reflector types a failed experiment?
Is there no warranty with these from the road builders?

I don't think they should ever have been using the nail on/stick on type reflectors unless placed outside the traffic lanes (so just to the left of the hard shoulder delimiter and just to thr right of the central reservation delimiter, with all other studs (the ones that could be expected to be driven over as traffic changes lane) being of the traditional "embedded" type. This is how they do it in the UK anyway and it seems ok.

tonc76

murphaph wrote: »

Thanks for that. I see the minimum standards expected of contractors but I don't see anything about failure rates triggering replacement post guarantee period. Have I overlooked something?

It's certainly a start...something worth asking the Minister of Transport about. It's his job to make sure our roads are safe and if cats eyes are failing en masse and not being replaced (as is the case on many stretches of road) then it's something he needs to address with the NRA and local authorities.

They talk a good talk when it comes to road safety but all too often they concentrate on speeding and neglect "simple things" like maintenance of the road markings.

I would expect the LA/NRA to replace studs that are faulty outside of the guarantee period as the contractor cannot be left on the hook forever.

The inclusion of CE marking for road studs in accordance with the relevant EN should remove most if not all of the sub-standard studs from use.

murphaph

tonc76 wrote: »

I would expect the LA/NRA to replace studs that are faulty outside of the guarantee period as the contractor cannot be left on the hook forever.

Absolutely. That's really the point I'm trying to make: the roads authorities are absolutely rubbish at replacing missing/faulty studs/inserts. I don't think there's any concerted plan among any local authority to spot/rectify these problems.

tonc76 wrote: »

The inclusion of CE marking for road studs in accordance with the relevant EN should remove most if not all of the sub-standard studs from use.

From initial installation yes, but it does nothing to address the lack of maintenance by the councils. The cats eye insert needs periodic replacement as it is a moving part that eventually fails. The little reflector beads can also become dislodged. It seems to me the councils just wait until the road is getting a resurface and only then are cats eyes replaced.

Zoney

The councils/NRA are a long way from proper maintanance of cat's eyes, given broken wire barriers aren't fixed directly! I'd draw people's attention to that before tackling the issue of cat's eyes!

murphaph

Zoney wrote: »

The councils/NRA are a long way from proper maintanance of cat's eyes, given broken wire barriers aren't fixed directly! I'd draw people's attention to that before tackling the issue of cat's eyes!

Maybe the barriers were damaged by drivers who couldn't see the path of the road ahead because of missing cats eyes ;-)