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South Salt Lake Journal

No idling in South Salt Lake. It’s the law

Feb 13, 2020 03:32PM ● By Bill Hardesty

In South Salt Lake, idling is not only bad for the environment, but it is also against the law. (Bill Hardesty/City Journals)

By Bill Hardesty | [email protected]

A common event during winter, which also happens at other times too, is an inversion. We hack our way through it until a storm comes to blow out the polluted air. Typically, cold air is on top of warm air. However, at times, like after a snowstorm, cold air is below warm air. It is inverted. When an inversion occurs, the warm air traps the cold air in the valleys. Each day of the inversion increases the levels of fine particulate pollution. 

Fine particulate pollution or PM2.5 refers to atmospheric particulate matter (PM) that have a diameter of less than 2.5 micrometers. These PMs are so small they are 30 times smaller than a human hair. 

When measuring air pollution, bigger is not better because these fine particulates are small and they are able to travel deeper into the lungs. 

"While larger PM10 particulates can compromise respiratory and cardiac health, smaller particulate matter (PM2.5) poses the greatest risk because it can penetrate deeply into the lungs where it can cause inflammation and damage to the lung tissue," according to the Utah Department of Environmental Quality (UDEQ).

Number one on the PM2.5 source list is vehicle use. We drive down the freeway and messages flash above encouraging carpooling or limiting our driving on certain days. But what about idling?


We do love to idle. Look at any fast food drive-through or a bank on payday or an elementary school at the end of the school day. Somehow it is easier to keep the car running, then turning it off and on.

However, "Reducing idle time can improve air quality and reduce fuel costs. Did you know that 10 seconds of idling can use more fuel than turning off your engine and restarting it?" That’s according to the Utah Clean Air (UCAIR) website.

Another fact from the UDEQ is that "Computerized controls in today’s vehicles bring the engine and catalyst up to their operating temperatures, more quickly when the vehicle is moving than when it is idling. The catalytic converter that reduces emissions also operates much sooner if the car is driven right away rather than idled. Even on the coldest day, it takes a modern vehicle less than 5 minutes to warm the engine if the car is moving. In contrast, it takes the engine almost twice as long to warm up if the car is merely idling."

The website also mentions that there is little wear and tear on engine parts with frequently turning the vehicle on and off.

Illegal with enforcement issues

Need another reason why not to idle? In South Salt Lake, idling is against the law. Municipal code section 10.8 states a driver cannot idle their vehicle more than two minutes. The first incident is a warning. Other incidents within 12 months bring a $50 to $200 fine. 

Sounds simple, right? Nope. The enforcement of this ordinance is difficult for at least three reasons. The first is 12 exceptions written into the ordinance. Some are obvious. Such as when you are stopped at a traffic light or you are servicing a vehicle or emergency vehicles in their official duties. 

Other exceptions are less obvious. Such as to operate your heater when it is below 32 degrees or your air conditioner when it is above 90 degrees or to heat up the defroster to clear your windows or recharge a hybrid electric vehicle battery.

The second reason is another caveat written into the ordinance. It is not enforceable at businesses that have a drive-through if "a sign is posted informing its customers and the public of the city's time limit for idling vehicle engines" or the property owner adopts an "idle reduction education policy approved by the city."

The third reason is resources. This ordinance is enforced on a complaint basis. If the police receive a call regarding vehicle idling, an officer is dispatched to investigate.