There's a couple of items that I keep seeing, but don't know what they are. Can anyone help? 1: those blue poles with what look like solar panels on top. 2: those pairs of small rubber pipe that run across the road - I assumed they were some sort of speed measurement device, but - if so - don't cars turning off/overtaking and different length wheelbases thro them off?
Those rubber pipes count the vehicles passing. Although there would be no technical problem to record speed, I'm not sure if this is their main purpose. The wheels pass over first one pipe then the other. The gizmo in the grey box detects the order of the pressure chages in the pipes and records the direction that the vehicle is travelling.
When I was a tearaway teenager I thought that they were intended to perform a census of vehicle speed so as to let the fuzz know if they needed to deploy the hair driers. I found that by applying the rear brake of my motorbike at just the right instant I could rip the pipes out of ther fastenings! Haha!
I'm much more law abiding these days
Blue poles with solar panels seem to be atmosphere measuring devices (pollution?) or maybe just temerature and pressure. The solar panels provide the power for the recording device, and I'll bet they transmit the data in chunks by radio.
No shaggy dog, blue cameras point at reg plates. I thought LeMarchand meant those small poles about 5ft high with slanting solar panel on top and light grey detection devices under panel. The blue cameras are taller, have a hooded cameras pointing in each direction and a flexible aerial stickoing out of the top.
The blue poles which look like they have got a sort of funnel on its side at the top, are there to measure the speed of the traffic. They are erected by Trafficmaster, so that if you have one of their onboard displays, it will show the speed of traffic on main roads and motorways you are intending to use so you can spot jams. http://www.trafficmaster.co.uk/
for more info
Just for completeness, the green poles with boxes attached (4-10 feet high) are gas regulator vents. As they're so common but so few people notice them, I have photos on my website, plus a list of locations.
www.groups.msn.com/davidskingsburycollection