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The new overhead cameras you see at the Mount Hermon Road/Scotts Valley Drive/Whispering Pines Road intersection are solely for detecting the presence of vehicles in order to provide the best distribution of green time based on traffic demand. They are cost-effective replacements for in-ground induction loops that are cut into the pavement.
The cameras are not focused the driver, but rather the vehicle as it moves towards the intersection. As the vehicle enters defined areas or "zones" within the camera's field of view, the camera's processor detects a change in the "zone." An output is sent to the traffic signal's controller (the computerized "brain" housed in a nearby metallic cabinet controlling the intersection's timing) that says a vehicle is requesting green time for its direction.
There is no constant surveillance or archiving of these images. The camera view is a fixed focus, fixed location image (there is no zooming or moving the cameras once they are installed). The image is analyzed by the camera processor ONLY for the simple presence of vehicles within defined areas or "zones." The cameras are not equipped to read license plates or distinguish facial features.
The cameras to not record and store video. The data from the camera is analyzed by the processor in real-time.
Previously, the primary method of vehicle detection was done by cutting the pavement a few inches and installing a wire "loop" just below the surface.
These in-ground loops have both near-term and long-term costs. The labor for a work crew to saw-cut pavement while shutting down that lane of traffic, and the cost of material are immediate costs. The saw cutting of the pavement weakens its strength, resulting in shorter service life and more maintenance costs for pavement repair. When in-ground loops fail, the entire loop must be recut into the pavement again. Video cameras give us low cost options to change the detection boxes do to construction or lane shifts, while pavement loops do not.
Video detection cameras, like most electronics, have seen their costs steadily drop since the technology was first introduced. Installation is done above the surface of the road, and usually away from the flow of traffic. The pavement remains undisturbed and is capable of lasting longer. When cameras or processors fail, they are simply and quickly replaced without a great disturbance in traffic flow.
Green pavement highlights areas where bicycles and cars cross paths. The green pavement alerts both drivers and bicyclists to pay extra attention.
A bike box is a designated area at the front of a traffic lane at a signalized intersection that places the bicyclist ahead of queuing motor vehicle traffic during the red signal phase. The bike box increases visibility of bicyclists at intersections (the most common location for bicycle collisions).
It is also intended to prevent conflict between bicyclists and motorists continuing in different directions. For example, a bicyclist traveling straight through an intersection should be centered in the traffic lane giving a right turning motorist room to turn safely next to them. Likewise, a bicyclist turning left from a lane that can either turn left or go straight should be position in the center of the traffic lane in front of motor vehicles intending to travel straight so that their paths do not cross.
How to Use a Bike Box (educational video)
How to Use When Biking: When the light is red, use the bike lane to proceed to the front of the intersection and move into the bike box. Stop before the crosswalk and position yourself directly in front of waiting automobiles. When the light turns green, move through the intersection ahead of traffic. Use hand signals to tell drivers which way you’re turning, and move into the bike lane or to the right side of the street once you have passed through the intersection.
The bike box should only be used when the light is yellow or red. If you approach the intersection when the light is green, use the bike lane to approach the intersection and proceed normally.
How to Use When Driving: If you approach the intersection and the light is yellow or red, stop at the white stop line behind the green bike box. Keep the bike box clear to allow cyclists to use it. If people on bikes are in front of you in the bike box, allow them to travel first through the intersection.