A speedy drive-thru is essential for quick-serves but nowhere more so than in Toronto, where a long wait in line could get customers slapped with a $125 fine.

The city’s anti-idling bylaw, on the books since 1998, prohibits vehicles from remaining stationary with engines running for more than three minutes in any 60 minute period. With average wait times for drive-thrus clocking in at just more than three minutes, according to the 2007 Quick-Service Drive-Thru Performance Study, that could render a morning stop for coffee a punishable offense.

Toronto’s bylaw isn’t the only one of its kind. Cities across the continent have passed or are discussing measures that could affect how business is done in fast food’s fast lane. At least 23 municipalities in Canada have adopted, proposed, or are considering anti-idling laws or other restrictions that could affect drive-thrus, and cities across the U.S. are also jumping on board.

The reasons behind such measures vary among municipalities, but many cite a growing body of evidence alleging that drive-thrus are bad for the environment. A recent study conducted by students at Canada’s University of Alberta predicted that the cars idling in drive-thrus at 135 restaurants in the city of Edmonton, Alberta, produced almost 25 tons of greenhouse-gas emissions per day. Over the course of a year, that could amount to more than 9,000 tons of greenhouse gases released into the atmosphere. While the study says that number amounts to only about 0.05 percent of the city’s total yearly greenhouse-gas emissions, Peter Boxall, the University of Alberta environmental economics professor whose class conducted the study, says it adds up.

“It’s fairly significant,” Boxall says of the emissions from cars in drive-thru lanes. “And we’re not factoring in the cost of congestion or other traffic-related issues that come about as a result.”

There are other concerns, too. Toronto’s anti-idling bylaw was proposed by the city’s Board of Health in hopes of cutting down on health problems caused by air pollution. In 2007, Toronto Public Health estimated that traffic-related air pollution was responsible for 440 premature deaths and 1,700 hospitalizations—to the tune of $2.2 billion per year. Recently, the board of health recommended an even stricter regulation that would prohibit cars from idling more than 10 seconds an hour.

Vince Loffredi, a supervisor with Toronto Transportation Services, says there have been no recorded complaints made against cars waiting in drive-thru lanes under the three-minute idling limit, but that would likely change if the 10 second rule is adopted.

“What it might mean is that if you’re in a drive-thru, you’re going to have to shut your car off,” Loffredi says. “People might have to change the way they queue at the drive-thru.”

Other measures being discussed, however, would not be so lax. As concern grows about the environmental impact of drive-thrus, some cities are trying to make it harder to get permits to build the lanes, while others are talking about prohibiting the building of new ones entirely.

One such city was London, Ontario, where a group of citizens, led mostly by local high-school students, was pushing the city’s planning commission to pass a moratorium on construction of new drive-thru projects.

The thinking, says David Heap, a London resident who got involved in the movement as a parent, was for the city to stop the building of new drive-thrus until a carbon-dioxide emissions plan could be established for the city.

“The idea was that we should err on the side of caution before we approve more,” Heap says.