Those speed detecting cables across the road.
Discussion
Neonblau said:
I've often wondered about these.
Question for those in the know - presumably they count axles rather than vehicles - how do you translate that axle count into vehicle count? I'm guessing there is a set ratio per road type to allow for three or more axles.
The unit we used would calculate vehicle category by the axle spacing and the mass of whatever was driving over it - this was done in unit and the data we took later would show categories rather than raw data from air pulsesQuestion for those in the know - presumably they count axles rather than vehicles - how do you translate that axle count into vehicle count? I'm guessing there is a set ratio per road type to allow for three or more axles.
I'm sure there would be some false readings, but they'd be in the vast minority when you're taking statistical data from thousands of vehicle movements
the_lone_wolf said:
The unit we used would calculate vehicle category by the axle spacing and the mass of whatever was driving over it - this was done in unit and the data we took later would show categories rather than raw data from air pulses
I'm sure there would be some false readings, but they'd be in the vast minority when you're taking statistical data from thousands of vehicle movements
The report from the link I posted on the previous page. Axle spacing only: Classes 3 & 4 combined to obviate misclassifications.I'm sure there would be some false readings, but they'd be in the vast minority when you're taking statistical data from thousands of vehicle movements
https://www.whatdotheyknow.com/request/212921/resp... - is it the same kit you used? -
I've recently commissioned the installation of a few hundred of these around Cambridge as part of a 20mph-related study. They are for surveying vehicle type and speed. If you want to have a look at the typical data they produce/record, clicky below...
https://www.cambridge.gov.uk/20mph-speed-limit-nor...
If anyone wants to know anything else (about their use, rather than their technical workings), ask away. Some of the wilder speculation above is a bit silly.
https://www.cambridge.gov.uk/20mph-speed-limit-nor...
If anyone wants to know anything else (about their use, rather than their technical workings), ask away. Some of the wilder speculation above is a bit silly.
Edited by OpulentBob on Friday 17th October 13:42
Red Devil said:
The report from the link I posted on the previous page. Axle spacing only: Classes 3 & 4 combined to obviate misclassifications.
https://www.whatdotheyknow.com/request/212921/resp... - is it the same kit you used? -
Yep, MetroCount is the same manufacturer, I couldn't tell you the model number as it's been a few years since I worked in that office...https://www.whatdotheyknow.com/request/212921/resp... - is it the same kit you used? -
speedking31 said:
Swervin_Mervin said:
Where are they out of interest?
Around the junction of the A50 / A556 at Mere, Cheshire. May be related to the upcoming 'improvement' of the A556 from a 60 mph single carriageway road to a 50 mph limit grade separated dual carriageway.They are everywhere right now, in both Cheshire East and the South Manchester area. It could be one of 3 things I reckon.
1: It's just the annual monitoring that they do. They used to produce annual reports on changes in traffic characteristics, although it typically used to only be Greater Manchester Transport Unit (or TfGM now), not Cheshire.
2: Given that they are everywhere, including round Wilmslow, Stockport etc, it could be because of the SEMMMS Airport link road which will be approaching Secretary of State call-in soon I believe. They'd be monitoring and updating reports on the effects of the scheme if it's this.
3: It could be exactly as you note - the A556 link. That was very recently approved by SoS and will be moving towards the tendering process to start on site next year I think. In which case it could be monitoring by CEC or the HA to tweak further forecasts on the scheme impacts and what to do with the old A556 link e.g. downgrading of the signal junction as one example. Speed limits could be another.
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