Rubber hoses across the road...

[slofox]

Yesterday while out biking I came across the rubber hoses across the road thingy - usually for counting vehicles....this one was a little different in the it had an extra hose (or maybe two?) there as well.......haven't seen one like it before.....anyone else seen this setup?....any ideas what it was for.....?

[BOGAR]

It probably is still a count station but the two hose setup or 4 (2 for each lane) can better determine type of vehicle and give speed also. all depends on type of info required.

[bomma]

determine type of vehicle and give speed also.

+1

10 char you mofo

[slofox]

It probably is still a count station but the two hose setup or 4 (2 for each lane) can better determine type of vehicle and give speed also. all depends on type of info required.

Yeah - I think you are right. After posting I was thinking it through and it was a two lane situation and as I recall, the second set of tubes were shorter - hence measuring the left hand lane whilst the first set of tubes measured both lanes......my main concern was the fact that I was just a TAD over the limit....heh heh heh......caught myself thinking "hope that doesn't trigger a speed cam....." Specially after I had been so very good on the rest of the ride.....

[cooneyr]

It probably is still a count station but the two hose setup or 4 (2 for each lane) can better determine type of vehicle and give speed also. all depends on type of info required.

Spot on - the two tubes mean speed and vehicle type (13 different classes of vehicles) can be determined. Typically they are attached to a metrocount (Ausi built) counter. You can have one set of tubes right across a two lane (one each direction) road and also get direction and time each vehicle crosses the tubes.

The old single tube counters really suck and should be biffed. All you know is the number of axles that cross the tube. No directional info, no time, no vehicle classes.

Cheers R

[SeppoDave]

No, they won't trigger a speed camera, but they ARE there to measure vehicle speed. The LTSA require speed surveys to set the speed limits on roads in certain situations. These situations can be anything from safety surveys post-incident to local authorities trying to LOWER THE SPEED LIMIT on a given piece of road.

When they try to lower the limit from say 100 to 80kph, they roll out these devices and measure everyone's speed. If the mean and 85th percentile measured speed are pretty close to 80kph, then the authority will have a case to reduce the speed limit. They would have had to go through this procedure on Riverhead Rd and Karangahake Gorge last year when they were reduced.

My policy has always been to hit those measuring sensors at as fast a speed as possible, thus raising the average.

[Daffyd]

Depends on how far apart they are... If they're only a couple of feet apart they are counters only, set to trigger with different weights. (Quite often used for counting cycle movements.) The speed traps are normally 10 metres or so apart.

[slofox]

My policy has always been to hit those measuring sensors at as fast a speed as possible, thus raising the average.

I think I helped your campaign, Seppodave.........

[slofox]

Depends on how far apart they are... If they're only a couple of feet apart they are counters only, set to trigger with different weights. (Quite often used for counting cycle movements.) The speed traps are normally 10 metres or so apart.

Couple of feet - not ten metres.....

[<Rhino>]

Spot on - the two tubes mean speed and vehicle type (13 different classes of vehicles) can be determined. Typically they are attached to a metrocount (Ausi built) counter. You can have one set of tubes right across a two lane (one each direction) road and also get direction and time each vehicle crosses the tubes.

The old single tube counters really suck and should be biffed. All you know is the number of axles that cross the tube. No directional info, no time, no vehicle classes.

Cheers R

Cant argue with that. The man knows what hes talking about

[cooneyr]

No, they won't trigger a speed camera, but they ARE there to measure vehicle speed. The LTSA require speed surveys to set the speed limits on roads in certain situations. These situations can be anything from safety surveys post-incident to local authorities trying to LOWER THE SPEED LIMIT on a given piece of road.

This is wrong on two counts.

1. the LTSA does not use tube counters to measure speed (though they could be used for this), they use floating car surveys (floating in the traffic stream not the river ). The "floating" cars have a GPS which is used to record travel speed over a section of road.
2. the LTSA doesn't set the speed limit on roads. Dumb arse engineers such as myself who work for consultancies provide recommendations to councils (city and district) or Transit (now the NZTA) who then gazette (publicly notify) the speed limits after going through consultation with every tom dick and harry.

P.S. the LTSA doesn't exist anymore - it became LTNZ back in 2003ish and is now the NZTA. NZTA is a conglomeration of Transfund, LTSA and Transit.

If the mean and 85th percentile measured speed are pretty close to 80kph, then the authority will have a case to reduce the speed limit.

The current policy in NZ is in general to have speeds limits as high as possible (up to 100kph) unless there is a safety reason not to do so. Just because the mean speeds are lower than the posted limits is not a reason to lower the posted limits. There are a whole heap of roads around NZ that would have lower posted limits than they currently do if this was the case - Lewis Pass for example.

Also if the mean and the 85th percentile are "pretty close to 80kph" then the drivers on that road need to stop being robots.

My policy has always been to hit those measuring sensors at as fast a speed as possible, thus raising the average.

Well good for you but that will likely just attract cops to the area as some councils have a habit of passing on the speed data from counter sites to the police. Especially if there is a reoccurring trend of infringing.

Depends on how far apart they are... If they're only a couple of feet apart they are counters only, set to trigger with different weights. (Quite often used for counting cycle movements.) The speed traps are normally 10 metres or so apart.

Traffic counters are normally installed with 1m spacings between the tubes. It is very unusual to have different spacings. The counters are pneumatic i.e. when a car squashes the tubes the air rushes out the open end (attached to the counter) and triggers the counter. There are only about 4 WIM sites in NZ (Weigh In Motion).

Cheers R

[SeppoDave]

Damn! You caught me! Friggin consultants. So how many hours did you bill to Transit/LTNZ/NZTA while you wrote that post?

You say that they try to keep speed limits as high as possible. So what exactly are the circumstances when our favourite roads are reduced from 100 to 80? You might not be familiar with the roads I listed above, but Karangahake Rd was a great road for bikes which had lots of accidents(not just bikes), and Riverhead Rd had little traffic, very few accidents, and was just a basic country road. For one, lowering to 80 seemed reasonable (though a bummer), and the other seemed targeted at motorcyclists.

[Dino]

Thanks for all the info cooneyr

[cooneyr]

Damn! You caught me! Friggin consultants. So how many hours did you bill to Transit/LTNZ/NZTA while you wrote that post?

LOL - bills on its way to your place

You say that they try to keep speed limits as high as possible. So what exactly are the circumstances when our favourite roads are reduced from 100 to 80? You might not be familiar with the roads I listed above, but Karangahake Rd was a great road for bikes which had lots of accidents(not just bikes), and Riverhead Rd had little traffic, very few accidents, and was just a basic country road. For one, lowering to 80 seemed reasonable (though a bummer), and the other seemed targeted at motorcyclists.

Your right I'm not familiar with the roads so cant provide any direct comments. Some of the aspects that are taken into consideration though are density (no. per 100m or similar) of residential properties with access directly to the road; crash history, road cross section (is there a median); the environment (urban fringe, urban street, urban arterial, motorway, rural road etc). In general rural roads and motorways 100kph, rural roads with a high density of access but is not yet urban 80kph, urban fringe 70kph, urban arterial (median divided) 60kph, urban streets 50kph.

One point to note is the crash history may not be anything like what you expect. I know of quite a few locations around Canty that people believe to be very dangerous yet the crash rate is very low. Basically people don't think the site is safe so treat it with extra caution and hence don't have crashes. The reverse is also true. People may think "this is a great piece of road, fast, safe and fun" yet the crash history may be pretty bad.

Cheers R

[Pumba]

I too am one of those damm consultants that is a bit more familiar with the area and perhaps shed a bit more light. (probally not but I will still charge you for it

Karangahake Rd

Cant say I am fimiliar with this bit of road, and couldnt find it on wises (spelling might be off), but I fell you esentialy answered your own question if there have been a number of accidents, but if it is a road near, or, on the edge of Urban Metropolition Limit, as Riverhead Rd is, I suspect it is for the same reasons as below

Riverhead Rd

Riverhead road over the last 10 years has undergone significant amount of land developemnet, farmers close to the city carving up the old dairy farm into 10 and 15 acare block type stuff so all the life stylers can move in. This as a result has incresed the number of residents vechicle crossing on this streach of road. More vehicle crossings = more traffic sppeeding up and slowing down after entering and exiting. More residents mean more people to complain about the noise of the vehicles. Reducing the speed apeases the rate payers, and while it may piss us off as road users, the council does not directly collect a significant amount of its income from road users.