Earlier this week we reported on a study by American Traffic Solutions that claimed automatic school zone cameras are dramatically reducing the number of speeders.

The study said there was an 86 percent decrease in the number of speed violations near Lynnwood Elementary when comparing the 2009-2010 school year to 2010-2011, and a nearly 78 percent decrease in the Meadowdale school zone.

But when pressed by the Everett Herald, the company acknowledged the decline was far less dramatic once you factor in the reduced operating hours for the cameras that the City Council enacted last spring. (Editor’s note: a company spokesperson told us they did consider the reduced hours, but this new data suggests otherwise.)

Did the ATS camera study take into account how the change in hours reduced the number of Lynnwood school-zone speeding tickets? If so, how could ATS be certain that fewer tickets were being written because people were modifying their driving habits — the study’s key point?

To their credit, the people at ATS took our inquiry seriously. Their number crunchers went back to the data.

When they adjusted the findings to reflect for differences in how the city is using the cameras, the declines were far less dramatic, ATS acknowledged.

School-zone speeding tickets were down 44 percent outside Meadowdale High School (not 77 percent as the report suggested) and down 35 percent at Lynnwood Elementary (not the reported 86 percent), the camera company now says.

A company spokesman told the Herald the declines still demonstrate the program is having an effect.