Wires across roads

gscully

Anyone know the purpose of the black wires that stretch across various roads in the city? They're connected to a silver box. I'm guessing they measure speed or gather info for a survey.

Just curious...

SteelyDanJalapeno

counts vehicles

jammstarr

Passed over a few of those today - was wondering what they were all about.

jayboi

Id say its to count the traffic in the morning and what directions everyone takes, there were wires on every road at coming onto and off the roundabout at the hospital.

SteelyDanJalapeno

wouldn't be just in the morning....

Trick of the Tail

They're rubber tubes. The box at the end contains equipment that measures the change in air pressure when a vehicle goes over them, thus counting the vehicles.

I assume there's some way of accounting for multi-axel vehicles...

Andy

fricatus

alinton wrote: »

I assume there's some way of accounting for multi-axel vehicles...

I would assume so, and further, that they'd be able to make a separate count of those bigger vehicles so as to make for more useful information.

wmpdd3

The highway van was parked in front of the church on the dunmore road this afternoon, when the jeep in front of me nearly hit it, after taking the corner too fast. Even yer man jumped back onto the footpath.

Flyin Irishman

Are they being used to measure speed (ie. distance bwetween tubes/time it takes for front wheel to get from one tube to the next), or just being used to count vehicles?

giles lynchwood

Data collection

Trick of the Tail

Flyin Irishman wrote: »

Are they being used to measure speed (ie. distance bwetween tubes/time it takes for front wheel to get from one tube to the next), or just being used to count vehicles?

They can't measure speed because of the varying axel spacings with different vehicles.

A.

beazee

They could actually measure average speed on given stretch based on axle patterns.

Say first set of tubes notices axle pattern: 2 - 2 - 2 - 5 - 2 - 2 - 3
While the tubes at the end of tested stretch give you 2 - 2 - 2 - 2 - 3 - 2 - 5

Although you can't say which 2 axle car overtook another you could definitely calculate what was the avg speed for 3 and 5 axle vehicles.

jayboi

beazee wrote: »

They could actually measure average speed on given stretch based on axle patterns.

Say first set of tubes notices axle pattern: 2 - 2 - 2 - 5 - 2 - 2 - 3
While the tubes at the end of tested stretch give you 2 - 2 - 2 - 2 - 3 - 2 - 5

Although you can't say which 2 axle car overtook another you could definitely calculate what was the avg speed for 3 and 5 axle vehicles.

Yep it can do anything really after all it is a highly sophisticated doo-whackey

giles lynchwood

The installer´s van had International Data Collection on the side of it.
The Germans want to know everything:eek:

michellie

There all over the place, passed over a heap of them in the last 2 days!

fricatus

They're the whole way in the Dunmore Road and the ORR down by Tesco. Are they elsewhere in the city or just out that way?

wobbles

Passed a couple on the inner ring road as well

mecco

There is some load of them around town alright. With my tinfoil hat on, I started looking for cameras in case they were measuring speed!! Didnt see any though

I think they measure how busy a road is in each direction. So it wouldn't matter how many axles per vehicle went over the wires, but how often any axle went over them.

Makes sense for the city council to keep on top of that info I guess.

mecco

fricatus wrote: »

They're the whole way in the Dunmore Road and the ORR down by Tesco. Are they elsewhere in the city or just out that way?

They are around the Folly, and Inner Ring Road and Keanes Road too.

tonc76

I haven't seen the locations of these but they are generally set up on all approaches and exits from junctions in order to count the traffic volumes. When a vehicle passes over the tubing a pulse is sent down the tube to the collector box which records the passing vehicle. By laying them at various locations you can tell how many cars joined or left the road at a junction or between junctions. This information is then gathered and will be used for forward planning of resurfacing requirements, traffic signaling etc etc

billythepig

there across the road because they had nowhere else to put them:D

letsbet

1. Drive over them
2. Reverse back over them
3. Repeat 4-5 times

Just to mess with their stats. If we do it enough we might get a fly-over built

mecco

letsbet wrote: »

1. Drive over them
2. Reverse back over them
3. Repeat 4-5 times

Just to mess with their stats. If we do it enough we might get a fly-over built

This!! Or just drive over the first of the two wires, you'd end up with some guy at a screen watching cars disappearing into a black hole!!

dunphy3

mecco wrote: »

There is some load of them around town alright. With my tinfoil hat on, I started looking for cameras in case they were measuring speed!! Didnt see any though

I think they measure how busy a road is in each direction. So it wouldn't matter how many axles per vehicle went over the wires, but how often any axle went over them.

Makes sense for the city council to keep on top of that info I guess.

or to force heavy axil vechicals to use the new??? bridge.

chelloveks

dunphy3 wrote: »

or to force heavy axil vechicals to use the new??? bridge.

Or maybe to take back all the lovely new roads built here in the past ten years because the politicians realized the commie unionists in Waterford don't deserve em. They are going to put em together again up in Galway or somewhere that deserves em!

leduke

so thats what they are!!!! i thought they were the worlds smallest speed ramps!

mecco

dunphy3 wrote: »

mecco wrote: »

There is some load of them around town alright. With my tinfoil hat on, I started looking for cameras in case they were measuring speed!! Didnt see any though

I think they measure how busy a road is in each direction. So it wouldn't matter how many axles per vehicle went over the wires, but how often any axle went over them.

Makes sense for the city council to keep on top of that info I guess.

or to force heavy axil vechicals to use the new??? bridge.

You could be right but I don't get how they'd achieve that?

Heathen

letsbet wrote: »

1. Drive over them
2. Reverse back over them
3. Repeat 4-5 times

Just to mess with their stats. If we do it enough we might get a fly-over built

Or setup an "Occupy the Road Wires" facebook page and get a load of crusties to setup camp on them, to "stick it to the man" :rolleyes:

calvin_zola

They are all over cork and Limerick to I noticed dis week

jayboi

Gone this evening I think. Now we wait...

FatB

Although I know absolutely nothing about these wires, it seems pretty obvious that you could easily measure speed between both wires. if it was just for checking the amount of cars then surely one wire would be enough.

*Removes tinfoil hat*

Max Powers

FatB wrote: »

Although I know absolutely nothing about these wires, it seems pretty obvious that you could easily measure speed between both wires. if it was just for checking the amount of cars then surely one wire would be enough.

*Removes tinfoil hat*

It wouldnt measure which direction if only 1 wire. I was thinking about it, maybe someone might know; the system used would not measure 2 cars that travel over the wires at the same time would it.

letsbet

It should do as the cars would only hit one of the wires at the same time (unless one of the cars was going incredibly fast and/or the other one incredibly slow) as the wires are considerably closer together than the distance between the front and back wheels of a car so you'd imagine it could cope with that. Looking at it another way when the two cars going over the same wire at the same time one of them will already have gone over their first wire and so it should register both but it's an interesting point and it may cause a problem but you'd imagine they'd have that covered as in heavy slow-moving traffic it'd happen quite frequently.

danjo-xx

Seems very old technology wouldn't you imagine they would have something more digital or optical to get the required information.

wobbles

The wires can only measure per axle, not per vechicle. So if 2 cars and trailers go over, it may read as three vechicles. Same for lorries with more than 2 axles. Doesnt seem accurate enough to be of any use to find out traffic numbers

letsbet

The percentage of such lorries using those roads is relatively low as a percentage of the overall traffic I'd imagine so the results wouldn't be skewed too much and the relative amount of traffic would still be fairly accurate anyway.