what is this for?

count cars or measure speeding?

what do they do with the data?

both so they can upgrade the roads as nessasary I beleve

Oldschool from like the 70's-80's = rip handbrake on and tear them up.

Doesn't work anymore, they're taped down good. =]

Hardware: There is two becuase it measures traffic density and speed.
(Distance and time between the two) Divide all the data by two for each car having a set of axles.

Trucks would munt up the data a little bit, but i'm sure with today's technology, if 5 pieces of data come through rapidly that happen to be about the exact same speed it could interpret that as being a truck/semi and count it as 1 (or tally it as a "truck" which counts more for higher density traffic than a single car)...



last edited by Loki at 17:13:36 08/Nov/06

what i don't understand is why they have two. I don't know how it works.

I usually try and not go over them if possible.

they are usually in loops, so when a large metal object (your car/truck/bike) goes over them it creates a small electric current which is then recorded.

the older devices use tubes instead of cables and when cars run over them they register the air presure change.

sometimes they are spaced a small distance apart so they can also measure speed.

Similiar to this topic, anyone know what the dudes sitting beside a main road with a clipboard and a pen recording some data down are doing? I used to see them all the time in the valley after work.

same thing, counting traffic

usually they are counting traffic, but looking at it from different breakdowns.

like, how many trucks, buses, vans go this way or that.

or how many cars with 1 person in them etc.

anyone know what the guys standing on the side of the road with a thing that looks like a hairdryer pointing at cars is all about

Traffic counters (In Logan anyway and most councils) Record the Air pulse sent through the cables when something goes over it.

Jumping up an down on them will actually record something... but it usually just gets removed in the reduction of the information.

They read Speed, Direction of travel, Wheel base of Vehicle and Approx Weight.

Oldschool from like the 70's-80's = rip handbrake on and tear them up.

Still works, and is f***ING anoying, Because that pretty much totally destroy's a weeks worth on information. Which you, as a rate payer, will just have to pay to replace anyway. And they're a bitch to put in/take out too.

Mr Hardware, Fall asleep in Maths/Physics did you? Speed = Distance/Time.
Car Speed = 1 Meter (The distance they should be appart) / Time (between Air pulses).

usually they are checking your speed to see if you are breaking the speed limit.

sometimes they are only pretending to do this as a pretext to slow people down under the guise of high visability policing.

We use to increase the old traffic counters by dropping large rocks on them. You could also increase the reading by jumping on them... Ahhh the joys of growing up in a tiny country town.

I don't think the speed ones displayed a counter so we never knew if we were doing it right.

Anyone know what those guys standing on the side of the road in a dress with the hemm pulled up to show some leg are all about?

anyone know what the guys standing on the side of the road with a thing that looks like a hairdryer pointing at cars is all about

They're providing hair care services obviously.

Anyone know what those guys standing on the side of the road in a dress with the hemm pulled up to show some leg are all about?

Thats your mum trying to get some money to buy your dinner.

scooter, you forgot to say why theres two of them

its so people who jump on them have a harder time screwing up the stats, or kids with brick hammers who arent in the overweight categories

or i could be wrong. it does happen

I would say there's 2 of them at a set distance because different vehicles have a different length between the from and rear axel. if there was just one they wouldn't know how fast the car is going because the distance travelled between the wheels would be different for different vehicles.

Just a guess though.

hay duz ne1 no y their r 2 of them???

ne1?????

They have 2 so you can measure the time it takes to travel a distance.

Speed = Distance/Time

If you only had 1 you wouldn't have distance or time.
You'd have 1 single reading, which is useless.

(Or just read what Reload typed)

but I already read what loki and aragawn typed way back at 5:13~!#@!

too bad buster

I figured they'd use it to see if there was a lot of people over the speed limit and next few days hello mr plod with hairdryer!

More to do with Trafic Flow/Volume. See what areas should be upgraded.
People tend to complain a lot, and this is a way to have the data to tell them they're idiots.

But the data is used in support for projects such as new Roundabouts (Instead of T-intersections) or those stupid f***ing island slow down thinges (< Technical name)

last edited by Scooter at 21:53:36 08/Nov/06

do you mean those flat top speed jumps?

Rubba knows how fun those island thingies and roundabouts are in my car in the wet :D

And by fun, I mean f***ing gay.

okay...

I hate those flat top speed bumps, they are all around my suburb and make my 35 y.o suspension cry at anything over like 5km/h

Funny thing is it hasnt stopped s***, a few weeks ago some tard came flying around a the corner at the end of my street which even has the f*****ry slow down island things and then proceeded to lose it and smack 2 cars and plough through the front fence and into someones front yard a few houses down from me... lolz it was a bogandore how suprising!

Sure made a lot of difference :/

Also speed bumps and traffic chicane thingies make it easier for emergency vehicles to get where they are going quicker.

those traffic calming bumps make excellent launch points for trail bikes :D

so... whats the go with those pair of sneakers hanging from the power lines?

That's a chemical reaction caused by electricity that turns flying foxes into sneakers.

rofl @ chemical reaction

so... whats the go with those pair of sneakers hanging from the power lines?

i have been told that it means there is a drugdealer in the area but i don't think it is true.


last edited by ara at 16:18:49 09/Nov/06

I hate those flat top speed bumps, they are all around my suburb and make my 35 y.o suspension cry at anything over like 5km/h

I had the same troubles in my corolla. Leaf springs = ouch.
In my falcon though, i can take them at about 52-53km/h and the car just sort of lifts, and comes down on the down slope after the flat top.

so its like its one movement, not two. good fun.

i have been told that it means there is a drugdealer in the area but i don't think it is true.

me either... alchemically electrolyzed fruit bats it is! :D

if a car was on a treadmill, and it was in between two air tubes on the road, would it register?

the car wouldn't fly.

but the sneakers would

get a job!

52-53km/h

wow precise

yeah. right between the 50 line and the 55 line.

You can be precise in a falcon, they have easy to read speedometers. for fat/old people presumably.

There is no such thing as a faulty computer. It can only ever be faulty hardware, combination of hardware or software

If the definition of a computer is a combination of hardware and software that stores, retrieves and processes data though programmable instructions, then a computer with faulty software or hardware is also, by extension faulty.

Otherwise, your little witty comment could be applied to everything. There is no such thing as broken car. It can ony every be a faulty part.

Have read whole thread.

I thought these things only recorded the number of axles (sets of wheels), then it is assumed that dividing by 2 gives a close enough indication of traffic. Trucks as in semis f*** up the figures, but only marginally which is accounted for.

Now as for measuring speed, um no! How does it know when one vehicle finishes and another starts, what would happen is a 3 axle dump truck crosses then 15 minutes later a car, that would be on slow moving vehicle. Or some smart arse on his bike :) does a mono over the cable...

All they record is traffic numbers vs time of day.

All they record is traffic numbers vs time of day.

No.

anyone know what the guys standing on the side of the road with a thing that looks like a hairdryer pointing at cars is all about

LMAO

Anyone know what the girls standing on the corners of brunswick st are all about? I saw Herm talking to one the other day :)

Or some smart arse on his bike :) does a mono over the cable...

Why would it matter exactly?

One set of pulses (first and second cables) from a wheelstanding motorbike or 865 pulses from a very very long truck with lots and lots of axles.
It'll still measure the same speed and average out.

Now considering there aren't trucks with 865 sets of axles, I'd say that even if a normal truck did skew the results a little bit.
They're only after an indication of how much traffic is flowing how fast.

They're not trying to calculate a spaceship launch vector using pi to 8 zillion trillion million places to go to a distant galaxies 8 zillion trillion billion million miles to the power of 864 away.

How does it know when one vehicle finishes and another starts

because it isn't dumb

if two vehicles are to appear as one that is some f***n bad tailgating going on

Now as for measuring speed, um no! How does it know when one vehicle finishes and another starts, what would happen is a 3 axle dump truck crosses then 15 minutes later a car, that would be on slow moving vehicle. Or some smart arse on his bike :) does a mono over the cable...

Did you do physics or maths at schooL?

If you have 2 sets of cables half a meter apart you can calculate speed by measure the time an axle takes to get from the first set to the second. If there is more then 1 axle, like in all cases except for a "some smart arse on his bike :) does a mono" it makes no difference. Each axle has to eventually travel over both sets of cables.

They are usually only half a meter or so apart so lets do the math.

Car traveling down a road crosses the first set of cables and crossed the second set T seconds later. The cables are D meter apart.

The speed, S = D / T.

Since it is a car and has 2 sets of axles, the second set will result in the same measurement again.

This is how most speed cameras work, hence the dual flashes when you go past one speeding in a car.

yeh ara but your forgetting that bikes only have one wheel at the front and one on the back

also what would happen if i drove over it sidewaaaaaaaaaaaaaaaaaaaaaaz

ffs nerds

motorbikes are still made of metal. the vehcile is detected because it is a large chunk of metal passing over copper coils, generating an electric pulse in the case of the newer wiredevices or the wheels going over the tubes in the older style of device.

If you have 2 sets of cables half a meter apart you can calculate speed by measure the time an axle takes to get from the first set to the second. If there is more then 1 axle, like in all cases except for a "some smart arse on his bike :) does a mono" it makes no difference. Each axle has to eventually travel over both sets of cables.

Truck with 3 axles, how do you calculate?

Or how about a BDouble with 7 axles?

i guess the idea is that there should be six pulses total, but 3 of them are 'pairs' with roughly equal spacing between them

but now she/he/it has this idea that it's the metal in the car causing the pulse through electromagnetic hoobydooby not the wheeeeeeeeeeeeeeeeels

i really am amazed you guys can't grasp this simple concept.

it is irrelivent how many axles or wheels or whatever there are, they all need to pass over BOTH sets of cables/tubes/whatever.. the time is between the pairs of measuring devices, not the pairs of axles.

it could be a wheel barrow and it would still work.

i really can't make it any simpler then that.

but now she/he/it has this idea that it's the metal in the car causing the pulse through electromagnetic hoobydooby not the wheeeeeeeeeeeeeeeeels

yeah.. im just making this all up..

from the first hit on google.

How do Fixed Digital Speed Cameras work?

The fixed speed cameras detect the speed of vehicles by using piezo electronic detectors embedded into the road surface. These piezo detectors deflect slightly when a vehicle is driven over the detectors, which then triggers an electronic device that accurately measures the speed of the vehicle. If the speed of the vehicle exceeds the legal limit then a digital picture is taken of the offending vehicle.

it is very simular to how traffic lights work.

There are all sorts of technologies for detecting cars -- everything from lasers to rubber hoses filled with air! By far the most common technique is the inductive loop. An inductive loop is simply a coil of wire embedded in the road's surface. To install the loop, they lay the asphalt and then come back and cut a groove in the asphalt with a saw. The wire is placed in the groove and sealed with a rubbery compound. You can often see these big rectangular loops cut in the pavement because the compound is obvious.

Inductive loops work by detecting a change of inductance.

except traffic lights only have one array on sensors, not two a known distance apart.

last edited by ara at 03:08:21 14/Nov/06

my brother sometimes helps set these things up, so i asked him about how they work:

The tubes are blocked at one end, when something goes over it the air gets forced back the other way into the counter and it counts the pulses to work out what it is.

The ones we have a pretty tricky, depending on how close the pulses are, how much force the pulses hits with etc it can work out whether it is a car/truck/bus and how fast it is going.

They also work out which direction it is going in going by which tube it hits first (ours use two tubes.

The speed is worked out by it working out the time it takes for the car to travel between the two tubes.

hehehehe I used to take one wheel off our lawnmower and run it over those things to throw out their stats lol and I got them build a freeway entry right to our driveway by f***ing with the stats lol

But now there's lots of noise outside your house lol!

Splash sounds like a Taia.

Thats how the ones at Logan work, Air, not Electric.