How Much & Why People Idle Unnecessarily

How much do motorists idle unnecessarily?


There have been some studies conducted on how much idling motorists do, including unnecessary idling, which means long warm-ups, idling while parked in town, and in drive-thru lanes.


One comprehensive study published in the journal Energy Policy: Costly myths: An analysis of idling beliefs and behavior in personal motor vehicles was conducted by Vanderbilt University in 2007. The study found that Americans idle the engines of their personal car, truck or SUV an average of 16 minutes per day — only half of which involves being in traffic. The remaining eight minutes per day is split roughly evenly between warming up the engine and idling while parked, such as waiting to pick up a passenger. According to their calculations, sitting in place while the engine is running in non-traffic situations cumulatively wastes 1.8 billion gallons of fuel and emits 15.8 million metric tons (MMt) of CO2 on an annual basis in the U.S. This study does not include heavy-duty vehicle idling. “The CO2 emissions associated with idling accounts for roughly 1.6 percent of the total U.S. (greenhouse gas) emissions,” conclude the researchers. Remember this is for personal (light-duty) vehicles only. The researchers conducted an online survey of 1,300 U.S. residents in the fall of 2007 to determine their idling habits. (The average age of the respondents was 43.) The survey yielded not only the statistics cited above, but also a sense of how misinformed people are in their beliefs about idling.


Reasons why it is customary for motorists to allow their vehicles to idle


1. Lack of awareness. Most of us are simply unaware excessive idling is harmful and wasteful. Gradually, the word is getting out there, mostly from within the school environment and the growing number of idle-free initiatives and laws.


2. Perceived as necessary. Decades ago, people were taught that it was necessary to idle for proper engine warm up (prior to the advent of fuel injection in the 1980s, carburetor equipped vehicles needed more warm up time to prevent the possibility of stalling in traffic). Despite the advent of fuel injection and other technologies that have generally eliminated the need for extended idling, the myth persists that warming up is good for the engine when the exact opposite is true. For modern vehicles, once the oil has circulated throughout the engine (usually 30 seconds or less), it is best to drive the vehicle to complete engine warm up and to allow other mechanical components to warm up as well.


3. Optimal comfort. In the spatial environments of our homes and vehicles, we naturally tend to be accustomed to keeping our bodies in a comfort zone. A fully warmed up or cooled down vehicle cabin achieves this goal. But there is a high price — especially collectively — to be paid for prolonged warm-up idling, using remote vehicle starters or sitting in a parked idling car to keep warm or cool. Responsible people will choose to sacrifice a few minutes of optimal comfort to improve our air quality, save energy, lessen their carbon footprint, while saving money in avoiding fuel use and engine wear.


Ways motorists typically idle vehicles (all avoidable)


• Waiting for passengers

• Stopping at railway crossings, road construction zones, or border crossings

• Running quick errands

• Sitting in drive-through lanes

• Waiting to refuel or to have the car washed

• Stopping to talk to an acquaintance or friend

• Sitting in a car while using a smartphone/mobile device

• Preparing to leave the house (warming up)