What are the two cables in some roads?

Vanilla · 9 Jul 2009 at 15:06

You know the ones i'm talking about. You'll be driving down a road and all of a sudden there will be two black cables in the road, a foot apart, attached to a box at the side of the road.

What are these for? Speed or traffic volume? They've popped up EVERYWHERE in my local area recently.

I only ask because yesterday I saw a set of them where there is an existing speed camera. They were set up right where the white speed camera lines are. So I don't see why they would be looking to get average speed there and there would be no incentive to put a speed camera because there already was one.

Ucof · 9 Jul 2009 at 15:08

Long answer: They can either check the speed of the vehicles passing over them (by which pipe pressure changes first) or they can just count the number of vehicles that pass over them, and at what times of day.

Short answer: Traffic monitoring.

GinG · 9 Jul 2009 at 15:09

Ucof said:
Long answer: They can either check the speed of the vehicles passing over them (by which pipe pressure changes first) or they can just count the number of vehicles that pass over them, and at what times of day.

Short answer: Traffic monitoring.

Interesting, didnt realise they could tell the speed. I thought they were there just to monitor how many cars pass.

kaiowas · 9 Jul 2009 at 15:09

Traffic flow monitoring, they tend to be set up in clusters to measure traffic flows in to, out of and inside a particular area. Usually done to assist with planning traffic management and new developments etc.

Sin_Chase · 9 Jul 2009 at 15:10

I like to stop and reverse and go over them again and again and again.

Bwahahaha, screw your stats!

iaind · 9 Jul 2009 at 15:58

http://forums.overclockers.co.uk/showthread.php?t=18011258

Dup · 9 Jul 2009 at 16:07

ITS A TRAP!

Stop immedaitely and go the other way.

djbenjo · 9 Jul 2009 at 16:33

Recently there have been loads of these next to speed cameras - checking % of speeders in a particular location no doubt

Liquidfox · 9 Jul 2009 at 16:48

They put a few up near mine where's theres been a few cases of people pulling out onto a busy bypass and being plowed into...

I'm expecting a speed camera shortly

RichieM · 9 Jul 2009 at 16:50

I belive the single ones are for traffic volume and the double ones (two boxes a few feet apart) are speed sensing. AFAIK the speed ones are purely data collection i.e. Police cannot "connect" to them to check speeds

Skeeter · 9 Jul 2009 at 20:37

The single ones are ones that are broken...

There should always be 2 pipes accross the road to be able to establish the direction of the traffic aswell as the amount. There no point in knowing how many cars went by unless you know what direction they were going in!

A couple have sprung up around me recently, on a road that is getting more and more use as it comes up on TomTom as the fastest route from the south coast up to Bath/Bristol areas, yet is actually a B road not big enough for all the lorries that keep arriving on it!

Amoeba · 9 Jul 2009 at 21:04

Pretty sure it's nothing to do with speed - the lack of distance between them and the varying size of vehicle's wheels would mean the stats were pretty inaccurate.

iaind · 9 Jul 2009 at 21:57

Amoeba said:
Pretty sure it's nothing to do with speed - the lack of distance between them and the varying size of vehicle's wheels would mean the stats were pretty inaccurate.

As well as the amount of flex in them.

Viper² · 9 Jul 2009 at 22:07

To tell them if enough people drive down the road so they can put a speed camera there and get some cash?

iaind · 9 Jul 2009 at 22:09

Viper² said:
To tell them if enough people drive down the road so they can put a speed camera there and get some cash?

Lol I love the conspiracy theories about speed cameras.

To measure traffic volumes to plan contraflows/traffic calming etc

MrMoonX · 9 Jul 2009 at 22:16

Viper² said:
To tell them if enough people drive down the road so they can put a speed camera there and get some cash?

probably this just so they can cash cow us

Gaygle · 9 Jul 2009 at 22:38

Amoeba said:
Pretty sure it's nothing to do with speed - the lack of distance between them and the varying size of vehicle's wheels would mean the stats were pretty inaccurate.

Abraxaz1 · 9 Jul 2009 at 22:42

Oh Gawd not this again...
Don's tin foil cap & grab's some popcorn....

Hxc · 9 Jul 2009 at 23:07

A guy on here who works for the government doing car-y things (I forget exactly what) said they could be used for speed, so I believe him.

Housey · 9 Jul 2009 at 23:12

Could be my anti-bike cheesewire?