Cameras in Utah...

Do they look like any pics from this link?

http://www.poi-factory.com/node/6698

Miss POI

Hmmm...well, that answered my question...the cameras look exactly like these two:
http://www.poi-factory.com/images/traffic1.jpg
http://www.poi-factory.com/images/traffic2.jpg

So how do they work? Is there someone watching TV monitors...looking for the right time to change the signals?

This comes as quite a surprise...Utah doesn't seem like the place where you'd find that sort of intelligence. (I'm a Californian stuck in the lame state btw)

Now that I think about it, Utah *needs* red light cameras! It's not uncommon to see 4 or 5 cars run a red light here...no I am not exagerating...Utah drivers are really *that* bad. I think just a few red light cameras would be able to fully fund the state's education fund.

Usually red light camera's are mounted on separate poles. In my area, I asked one of my local police friends what those boxes/camera's were on top of some of the lights. He told me some are for detecting traffic and helping the computer to 'decide' when to extend green phases on the light sequence. Other boxes are for the police and firetrucks so they can change the light at will. And others are taking live motion pictures that can be used when there are accidents.

Usually those "optical sensors" are some sort of infrared sensor that let's the signal know when something is stopped at the line. These are replacing the old coil under the pavement type of sensor.

You will probably note that they may have drawn a little bicycle icon on the ground in the stop line and there may be a sign nearby telling bicyclists to change the light to green, stop on that icon.

These sensors are an improvement since they can better detect small and/or not much metal objects waiting for the light (bicycled, mostly plastic motor scooters, small motorcycles, etc.

PT

Thanks for the info guys!

Explanation of what you seen.

Video image vehicle detection system (VIVDS)

More cost-efficient than loop detectors.
VIVDS cameras are also used to monitor
traffic levels and perform traffic counts on
freeways and on arterial roads. Although
these cameras are not red-light cameras per
se, VIVDS cameras are often used in red-light
camera installations as the mechanism to
detect when vehicles have entered the
intersection.

Traffic signal preemption Intersections

MIRT
3M Opticom®
Tomar Strobecom®

traffic signal preemption are optically-based communications systems. The transmitter (strobe head located in the vehicle), the detector (also known as the “receiver” normally located on or near the traffic signal), and the optical medium between them (air).

Red Light Enforcement Cameras

An inductive loop detector or a VIVDS camera monitors the area just beyond the stop line. When the signal turns red, the detector is activated. When it detects a vehicle passing the stop line, it signals the red-light camera, which then takes two or more pictures of the vehicle, usually with a telltale camera flash. The lens is focused on the violation area so that a clear view of the vehicle, its license plate, and the signal is visible. Additionally, the controller timestamps the image and records other pertinent details, such as location, direction of travel, and length of time the signal was red. These cameras may be either film or digital, and newer cameras often also collect a short amount of video in conjunction with the still frame photos. Periodically, the film or digital media is collected and the photos examined. In cases where the photos clearly show the vehicle running the red, a citation is sent to the registered owner of the vehicle. If the registered owner was not driving, they can submit an affidavit affirming such and naming the person who was driving. Photos of in intersection before trip was sensed, non-violations or of situations that are less definitive are discarded.

Bob