CHICAGO (CBS) — School zones are supposed to be safe places for kids to walk or ride their bikes to get to school.

Signs warn drivers to slow down to 20 mph, but CBS 2′s Dave Savini found kids could actually be in danger from — of all things — speeding school bus drivers.

He calibrated a radar gun with one belonging to the Illinois Secretary of State Police. Together, they went looking for bus drivers speeding in school zones, the ones that have flashing warning lights.

They caught bus drivers, with children aboard, traveling at 31 mph, 34 mph and 41 mph within the zones.

Since March, the 2 Investigators monitored school zones in school districts serving Aurora, Plainfield, Oswego, Barrington and Crystal Lake.  Aside from the yellow buses, Savini caught a Pace bus and a Kindercare bus driving too fast.

Illinois Secretary of State Police Sgt. Dan Bonneville pulled over speeding bus drivers.

One who was caught driving 36 in a 20mph zone declined comment when Savini questioned her about her speeding. Then, she got on the radio and told a dispatcher about the radar trap.

But even with that warning, the speeding did not stop. Another driver was pulled over for going more than twice the school-zone speed limit — 41 mph.

“I guess I just didn’t realize that,” the driver told Savini.

Bonneville was surprised so many bus drivers were caught speeding.

Kristine Liptrot with Oswego Community Unit School District 308 was not happy about the speeding drivers.

“They have precious cargo,” she says. “It’s never acceptable for our bus drivers to be exceeding the speed.”

A bus that was speeding was blamed for the 1998 death of 10-year-old Kristie Talley, who was riding her bike to her Carpentersville school.

The Talley family’s attorney, Tony Romanucci, says the girl was struck in front of the school.

“If you are in a school zone and you’re driving a 40,000-pound yellow missile, and if you are not obeying the speed laws, it’s a recipe for death,” he said.

And it’s not just school zones. CBS 2 also captured a driver from Joliet Township District 204 in a 55 mph zone blowing by traffic with students on board and driving at excessive speed ranging from 70 to 75 mph.

In the Talley case, Barrington Bus Company settled a lawsuit for $1.2 million.

The bus companies and school districts involved in this report all said they would warn their drivers to slow down. Many of them thanked CBS 2 for the information.