You see them wherever you go in New Jersey these days. What appear to be long white cameras are placed at most intersections, and some believe it's a Big Brother watching you scenario, while other theorize the cameras are part of a Homeland Security program to track suspected terrorists.

Why are there traffic cameras at intersections? (trekandshoot, ThinkStock)

According to Steve Shapiro, a spokesman for the New Jersey Department of Transportation, the devices are not cameras, but rather image detection devices.

"They're able to detect when there are vehicles on the roadway, and they help with the proper signal timing, so it's a way to use technology to improve the traffic flow," he said. "They're not cameras like you would normally think of it, so it's not recording anything, it's not taking any pictures."

Shapiro said the devices can tell there's an object in the roadway, but they can't distinguish whether the vehicle is a passenger car or a truck.

"It just has the ability to know there is a vehicle in the roadway and therefore help with the timing of the light," he said.

According to Shapiro, when the device detects a vehicle in the road and there's no traffic coming from the road that intersects it, a green light might stay green longer, or a red light might change to green more quickly.

Shapiro said the bottom line is that the cameras have more to do with controlling traffic than observing motorists.

"These image detection devices are not recording anything, they basically just have the ability to detect that a vehicle is there but it's not a camera like you or I would think of a camera," he said. "It is technology that does help improve the performance of roadways, improve the traffic flow, try to ease congestion."