SOMERSET, N.J. — Police officers aren’t the only ones monitoring speed along the streets near Franklin Township Public Schools.

Transportation officials at the district are using their own radar gun to ensure that school bus drivers are staying within speed limits.

Transportation Supervisor Gary Peatick and Safety Coordinator Betty Lewis use the tool to occasionally spot-check buses on their routes and to follow up on speeding complaints from motorists and community residents. The district runs 16 of its own buses and contracts about 120.

Driving their own vehicles, Peatick and Lewis park along bus routes — especially in spots where they know speeding has been a problem — to perform the monitoring process.

Peatick said the idea stemmed from a conversation with a local law enforcement official about three years ago. When Peatick inquired about whether officers might be available to do speed checks of his buses, the official suggested a more efficient option: he could buy his own radar gun.

And so for $500, Peatick invested in a refurbished model, manufactured by MPH Industries, that had been used by police. The unit came with a 35-mph tuning fork for calibration.

Peatick, who has been with the district for eight years, says the benefits of using the radar gun are clear.

“It takes the guesswork out of following up on speeding issues,” he says. “It’s the accuracy of it as a tool that helps, because drivers will always have opinions about how fast they were going.”

But the radar gun has been used on more than one occasion to show that bus drivers weren’t speeding.

“Much like with video cameras, it’s not just a tool to prove drivers wrong,” Peatick says. “It works both ways.”

Peatick says that because of the size and loudness of school buses, it’s easy for people to perceive that the big, yellow vehicles are going faster than they really are.