Community Corner

Who Watches the Video from East Whiteland Traffic Cameras?

At smaller intersections, no one does.

Have you ever noticed a camera during your morning commute and wondered just who was monitoring the video stream?

Along major highways like Route 202, traffic cameras are owned by PennDOT and still frames can be viewed by the public 24 hours a day.

But what about the cameras perched above smaller intersections, like the one above the entrance to Uptown Worthington off Morehall Road (Route 29)? We sent a photo of that camera—a grainier version of the one attached to this article—to PennDOT spokesman Gene Blaum.

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Turns out, there's probably no one watching, or even able to watch, traffic through that camera. And that's by design.

"This photo shows a traffic detection camera that is tied into the traffic signal," Blaum said. "This is one type of traffic detection system. Others include underground loops or sensors that detect vehicles and a microwave detection system."

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The camera is owned by East Whiteland Township, despite being on state roads and mandated by the state. It's part of a "Video Detection System" that in most cases doesn't feed into a PennDOT office or other location.

"Typically, it is just tied to the traffic signal cabinet at the intersection," Blaum said.

More information comes from a PennDOT document called "Guidelines for the Maintenance and Operation of Traffic Signals" (PDF):

Video Detection System

Video detection systems are those that use video cameras for the detection of vehicles by sending a video image from the camera to a video processor in the controller cabinet. These systems in unique cases can be part of a closed circuit television (CCTV) system where the video feed is transmitted to monitors at the municipality or to a PennDOT Traffic Operations Center. The detection zones which are created for the camera(s) are typically viewed by plugging a laptop into the traffic signal controller. A benefit to video detection is that detection zones may be removed, replaced, or redrawn at any time. Other benefits include the detection of bicycles and motorcycles as well as a single camera being capable of detecting an entire approach.

A major benefit of video detection is that it is a non-intrusive technology. When used at intersections with multi-lane approaches it can become more cost-effective when compared to using loop detection. Video detection can be installed with little impact to moving traffic and when the pavement deteriorates and/or is resurfaced the camera still functions. Cameras must be mounted at a required height over the roadway in order to effectively detect vehicles. It should be noted that with those traffic signals where volume density (advanced) detection is used, video cameras mounted on mast arms generally cannot adequately perform volume-density detection. They must be either mounted close to the point of detection or at a much greater height.

Disadvantages of video image detection are the initial capital costs and that they are adversely affected by camera motion from the wind. In addition, light level and sun glare can cause problems. Other weather elements such as fog, rain and snow can affect its operations and result in false calls. Since the introduction of this technology, dramatic improvements have minimized these problems with today's cameras. Even so, preventative maintenance must be performed by qualified personnel.


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