[Raymond Sokalski] said the students use federal data showing that turning your engine off for waits of longer than 10 seconds is a net benefit. "All you're going to use is 10 seconds' worth of fuel to turn your engine on again," he said.

Come spring, students in Sokalski's Grade 10 geography class will be at the corner of Academy Road and Stafford Street interviewing motorists idling at red lights, and holding up signs. "The posters talk about the 10-second rule," Sokalski explained.

"We stand on the boulevard with a sign and a smile," said Sokalski, who's noticed more parents turning off their engines.