SAN ANTONIO -

These days, video cameras are virtually everywhere, keeping constant watch over our lives and many of us have just learned to live with them.

On Tuesday, a new type of camera started showing up along some downtown streets that had several people scratching their heads over what they're being used for.

"I saw them this morning after I dropped my son off at school," John Kirby said referring to a camera he noticed near the entrance of Central Catholic High School. "Looks like someone is monitoring what you're doing."

The cameras began appearing at intersections along McCullough and Brooklyn. Unlike other cameras with their unblinking eyes trained on roadways, these cameras were positioned much lower to the ground.

By Wednesday, several people noticed them and were trying to figure out what they were watching and why.

Some people speculated they were being used to catch red light runners or speeders, but it turns out they're just being used to count cars for a TxDOT traffic study.

"Really, they're just devices to help us take traffic counts. It's a method that one of our consultants uses," said TxDOT spokesman Josh Donat. "It helps us keep track of how many vehicles are out there."

According to Donat, the cameras are tracking the movements cars make leaving downtown and entering the highway system.

"This is a routine study. What we're looking at is what kind of traffic volumes we have in various locations," Donat said. "Basically it's about planning. We're going to use the data we receive from these consultants to help develop some solutions to address congestion in the downtown area and other places across the district."

While some traffic studies count cars with humans or other devices, the cameras help simplify the data collection process.

"You literally have to sit there and start counting by hand one by one, we use cameras to do that to make it a little easier and more efficient," Donat said. "We're going to record it, then go put it on a big screen somewhere and let interns count."

Donat said the cameras are only in place for about 24 hours, then they are moved to new locations in the study area. Over the next 3 weeks, the cameras will be placed in in roughly 3,300 locations around San Antonio and Bexar County.

While they may look like part of a high tech surveillance system, Donat reassures local drivers the cameras aren't being used to spy on people or collect personal data on drivers or their cars.

"We're not looking into cabs of the vehicles, we're not looking at license plates, we're just looking to count vehicles. That's all it is," Donat said. "It's part of the process of helping us address congestion and provide a safe system for everybody."

For a list of recent stories Tim Gerber has done, click here.