With all the talk of red light cameras, I’ve noticed many Napa intersections have cameras. Are these traffic cameras? If so, who monitors them? Can the public view them online like other traffic cameras?

You are not being recorded. There’s no need to smile. But smile anyway; no one likes a poker face.

Napa Police Sgt. Tom Pieper said cameras at most of Napa’s intersections are sensor cameras, excepting the new cameras — at the Jefferson and First streets and Big Ranch and Trancas intersections — which are used to catch red-light violators.

Sensor cameras detect traffic and are timed accordingly to change stoplights from green to yellow, yellow to red, red to green.

Edward Moore, the city’s senior engineering aide for transportation, concurred with Sgt. Pieper, adding that sensor cameras do not record traffic. So you can’t go to your computer to see what the camera sees — not in Napa, anyway. With a quick Google search, I found that in some cities one can view real-time traffic. Spooky.

Sensor cameras are not located at all signalized intersections. Rather, they are located at the intersections where the signal is new or recently changed, such as at Third and Soscol.

So what about other intersections? Moore said other intersections have wired loops in the ground that also detect traffic. These loops are embedded in or buried under the pavement.

Emergency response vehicles — police cars, ambulances and fire trucks — have built-in technology that sensor cameras pick up on, allowing them to change the timing on the signal to give those vehicles the right of way.

Moore said the city will also begin installing illuminated street signs by mid- to late-summer, making them easier to see from longer distances and in inclement weather (fog, heavy rain, etc.). Street signs will be lit from the inside, using LED bulbs, rather than fluorescent tubes. The first locations should be at the intersections at First and Soscol and Third and Soscol.

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Glad You Asked attempts to answer readers’ questions. Stumped by a question? Don’t turn red! Send your questions to dmontanez@napanews.com or call me at 256-2224.