Idle reduction

    Idle reduction describes technologies and practices that reduce the amount of time vehicles idle their engines. People let their cars idle for various reasons; especially in Louisiana, air conditioning often plays a part in why someone sitting in a non-moving car would want their engine running. But idling can also be a problem, and reducing the amount of time your engine idles can conserve fuel and reduce harmful emissions. According to the AFDC, "each year, U.S. passenger cars, light-duty trucks, medium-duty trucks, and heavy-duty vehicles consume more than 6 billion gallons of diesel fuel and gasoline—without even moving. Roughly half of that fuel is wasted by passenger vehicles." Idle reduction strategies can also reduce emissions of carbon dioxide, nitrogen oxides, carbon monoxide, particulate matter, and other harmful pollutants.

    Why Care About Idling?

    Personal Vehicles

    "Personal-vehicle idling wastes about 3 billion gallons of fuel—generating around 30 million tons of CO2 annually in the U.S."

    For everyday drivers, the best way to reduce idling is to simply turn the key when stopped for 10 seconds or more, except in traffic. There are a myriad of situations in which people might allow their car to idle, and the simple solution is to turn the engine off if you'll be idling for any extended length of time. When going through a long drive-through line, consider turning off your engine or, even better, parking and going inside the building. When waiting for passengers, keep the engine off while you wait.

    According to the US Office of Energy Efficiency and Renewable Energy (EERE), "It’s especially important for caregivers waiting to pick up schoolchildren to minimize idling because vehicle emissions are more concentrated near the ground, where children breathe. Poor air quality can contribute to asthma and other ailments, and children’s lungs are more susceptible to damage than adults’ lungs are."

    When considering idle reduction strategies, you may be worried about possible damage to your vehicle. "It will hurt my car if I keep turning it off and on again!" you might think. The truth is that under normal use, passenger-car drivers can turn their engines on and off without concern about wearing out the starter motor or the battery prematurely.

    According to the AFCD, "Starters and batteries are much more durable now than they were in the past," and "current vehicle owner’s manuals, which contain information on how to get the best and most economical performance, often recommend avoiding idling." Driving the car is better than idling; the car warms up and reaches optimal operating temperature more quickly by driving than idling. Since idling wastes fuel, reducing your vehicle idling can also save you time and money.

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    School Buses

    School buses are notorious idlers; bus drivers often turn on the engine while waiting for students to board or exit the bus at the start or end of the school day, idling for extended periods of time. Much like passenger vehicles, however, this idling increases the harmful emissions around schools, which is particularly dangerous for students.

    According to the US Environmental Protection Agency (EPA), "Diesel exhaust is designated 'carcinogenic to humans' by the International Agency for Research on Cancer (IARC). It contains significant levels of particulate matter (PM). These particles can lodge deep into the lungs and heart and are linked to premature death, aggravated asthma, and decreased lung function. Children are more susceptible than healthy adults because their respiratory systems are still developing and they have faster breathing rates."  Considering the incredibly high number of buses and passenger vehicles that idle on school property on any given morning or afternoon, this information should be concerning.

    School bus drivers can do their part by reducing the amount of time they idle their school buses. Though some drivers may believe that idling is necessary to warm up the bus's engine, the EPA states that "school bus engines do not need to idle more than a few minutes to warm up. Engine manufacturers generally recommend no more than three to five minutes of idling." 

    The EPA also recommends that school districts set up a school bus idle reduction policy. The policy should, at a minimum, include the following:

    • Buses should typically be moving whenever the engine is on.
    • Engines should be turned off quickly after arriving at loading or unloading areas.
    • Buses should not be restarted until they are ready to depart.
    • Morning warm-up idling time should be limited to manufacturers' recommendations.
    • When possible, shorten commute times for children.

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    About 500,000 long-haul trucks cross U.S. highways each day. Truckers are required to take a 10-hour rest after 11 hours of driving. As the trucks idle their engines during rest periods they use approximately 838 million gallons of fuel per year, increasing both fuel costs and harmful emissions. According to the EPA, there are several benefits to reducing long-duration idling, including:

    • Decreasing fuel costs,Image from the EPA
    • Decreasing engine maintenance costs;
    • Extending engine life;
    • Improving operator well-being by decreasing noise levels; and
    • Decreasing emissions that are harmful to the environment.

    Some idling solutions merely require awareness and behavioral adjustments. For example, turning off the vehicle engine while waiting at train crossings, bridge lifts, and other stops presents no negative outcomes for most drivers. Temperature-controlled waiting rooms at delivery destinations provide a nonvehicle solution for driver comfort.

    In cases where power is required onboard the vehicle, a variety of technologies may be considered. Certain onboard equipment can be used anywhere. When a truck is at a station with the proper infrastructure, truck stop electrification enables trucks to plug into the station for power and other amenities that are otherwise provided by onboard fuel.

    Some examples of idle reduction technology fleets can consider are:

    • Engine idle management systems simply shut down a vehicle’s engine after a preset amount of time, such as 3 minutes.
    • Vehicle operators who need heat for the cab or passenger compartment might consider air heaters. These units use much less fuel than idling an engine. Engine block heaters warm an engine (or keep it warm) to avoid the prolonged idling required for the warm-up of some diesel engines.
    • Auxiliary power systems provide power for HVAC, electronics, and other devices. Some systems provide power for power take-off (PTO) equipment.
    • Electrified parking spaces (EPS) allow truck drivers to shut off their engines and power HVAC, electronics, and more with electricity.
    • Some fleet management telematics systems enable the monitoring of vehicles’ idling times. Identifying “high idlers” or unexpected idling patterns may be a first step in devising a plan to reduce idling.

    Though some idling for trucks may be unavoidable, there are steps companies and drivers can take to be more aware of the consequences of idling and reduce unnecessary idling throughout their fleets.

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