Is it legal to leave your car running to warm up in the St. Louis area?

ST. LOUIS – As the St. Louis region receives its first measurable snowfall this season, it’s a friendly reminder that colder, icier and snowier days are just around the corner.

Of course, it’s that time of year again when you might be tempted to start your car, let it run, and take a quick step back while it warms up to combat frosty windshields and cold interiors.

These few steps may seem like a harmless way to prepare for winter conditions, but be warned: This handy shortcut could land you in legal trouble.

Is it legal to leave car running to warm up in St. Louis? Or elsewhere in the St. Louis area? Or in the states of Missouri or Illinois?

Here you can see some laws worth knowing in more detail. Many refer to the rules for warming up a car as “idling” or, as environmental experts put it, “running the engine while the vehicle is parked.”

St Louis City

A St. Louis city ordinance that first went into effect in 2008 prohibits people from “idling” a vehicle under various time and temperature conditions.

The ordinance says it is illegal to leave a vehicle “idling” for more than five minutes per hour or 10 minutes per hour when temperatures are below freezing.

There are some exceptions for emergency vehicles, vehicles used to transport disabled people or people with special needs, and other operational or testing purposes.

Any reported violation of this ordinance may result in fines of up to $150.

St Louis County

St. Louis County does not specifically prohibit warming up a car in cold temperatures, but there are restrictions on warming up a car under the county’s air pollution policy.

The county’s air pollution ordinance says it is illegal to leave a vehicle “idling” for more than three minutes while parked, stationary or stopped “unless the engine is used to operate a loading, unloading or processing device.” used”.

The only exceptions to this apply to emergency vehicles.

All reported municipal code violations may result in fines of up to $1,000.

Missouri

There is no law in the state of Missouri that specifically prohibits warming up a vehicle in cold temperatures. However, there are some restrictions in the state if the vehicle being warmed up is a “high performance vehicle”, such as: B. Buses and semi-trailer trucks.

The Missouri Department of Natural Resources has issued regulations making it illegal to idle “heavy diesel vehicles” for more than five minutes per hour in eight Missouri counties, including five in the St. Louis area. It is part of efforts to control air pollution.

Counties subject to this restriction include:

• St Louis City
• St Louis County
• Franklin County
• Jefferson County
• St Charles County
• Clay County (KC Metro)
• Jackson County (KC Metro)
• Platte County (KC Metro)

The consequences of violations may vary depending on the community in which a violation was reported.

Illinois

The state of Illinois, which includes several counties in the St. Louis region, prohibits unattended warming up of a car in most cases.

The Illinois Vehicle Code states: “No person driving or responsible for a motor vehicle shall leave it unattended without first stopping the engine, locking the ignition, removing the key from the ignition, effectively applying the brake, and while standing.” Turn the front wheels towards the curb or the side of the road whenever there is a noticeable gradient.”

This probably makes it illegal to leave a running vehicle idling unattended, even if you go in briefly to warm up while your car warms up.

There are some exceptions for police officers and people authorized to drive emergency vehicles as part of their duties.

There is also a provision in Illinois vehicle law that states that a vehicle is not considered “unattended” if it is locked and running with the engine started via a remote starter system.

However, the Illinois Vehicle Code also prohibits leaving a vehicle idling for more than 10 minutes in any given hour, even if someone is attending to the moving vehicle.

Do any rules apply to remote starting cars?

As specifically stated in the Illinois Vehicle Code, it is not necessarily illegal to unattended start a car with a remote starter system in Illinois. Since Missouri has no law governing such matters, the same could apply there.

However, all local and state “idling” rules must be followed. Therefore, as with most laws that apply to drivers in the St. Louis area, a period between 3 and 10 minutes is probably the optimal value for how long a car can warm up while running and parked.

MotorBiscuit.com explains that dozens of other U.S. states have similar laws governing idling with remote starter vehicles, such as Missouri and Illinois, even though there appears to be no national law against idling a car or using a remote starter to do so to warm it up.