Big Brother isn’t watching you drive along the streets of Lawrence. But new camera-like devices atop traffic signals may be fooling some drivers.

“We do get a few folks that insist they are cameras with video/film capability, but they aren’t,” City Manager Mike Wildgen said.

Instead, the devices monitor when traffic is stopped at an intersection and change the signal from red to green to keep cars moving down the road.

As many as 20 of the new devices have been installed along Lawrence streets in the past three years, replacing below-ground versions that were more costly and more difficult to maintain.

“We’ve probably got between 10 and 20 intersections that do detection that way,” David Woosley, the city’s traffic engineer, said of the new signal-mounted sensors. “Anything we’ve done in the last couple of years — anything we’ve upgraded — we’ve done that way.”

The latest sensors were installed on new Sixth Street signals, at Lawrence Avenue, Kasold Drive and Monterey Way. City Hall has received several calls from motorists asking whether the devices are used to record traffic infractions.

“Modern technology can sure put people on edge, apparently,” Wildgen said.

Several drivers who stopped this week at the Westlake Ace Hardware store at 601 Kasold Drive, however, weren’t fooled by the sensors.

“I thought they were for traffic control,” said Jeff Webb of Lawrence.

Some Lawrence motorists have been wondering if devices like these at Sixth Street and Kasold Drive are cameras used to spy on motorists. City officials assure residents that the devices are mere traffic sensors, which help traffic flow smoothly through intersections.

In fact, no regulations exist that allow Lawrence or any other Kansas city to record traffic violations using remote-controlled cameras.

“Absolutely not,” Woosley said. “State law does not permit that.”

He said the above-ground sensors were cheaper and easier to get to than devices embedded in the pavement. The new signal-mounted machines cost about $17,000 for a major intersection; below-ground versions could cost between $18,000 and $32,000 for the same intersection.

Officials said they didn’t intend for drivers to think they were being watched by cameras. But they concede the devices may have made some Lawrence residents a bit more cautious.

“It might, accidentally, for just a few people,” Woosley said. “The average driver probably hasn’t paid attention to know it’s up there.”