Stop the School Buses from Idling

It’s end of August already and you know what that means…’s almost time for Back To School. I’m happy to say that I’ve seen a lot of  news about  eco friendly school products from recycled notebooks, stainless steel lunch boxes, reusable snack bags, and book bags made with recycled plastic. If you don’t know where to buy them, just Google eco friendly lunch boxes or snack bags and you’ll get literally thousands of resources.

Today, though, I am thinking about the air children breathe due to idling school buses.

No idling School Bus Program

No idling School Bus Program

Yep. I’m thinking about the school buses that idle while waiting for their passengers. In fact, this also goes for those of you who idle while waiting for your kids at the bus stop or in front of the school.

My daughter did a power point presentation last year on school bus idling and we learned a lot about why it’s not so cool to keep the buses idling. According to the Environmental Protection Agency (EPA), idling school buses not only cause air pollution but  they are bad for the engines, cost more money for fuel and they are dangerous to children’s health. According to EPA, unnecessary school bus idling pollutes the air, wastes fuel, and causes excess engine wear.

Idling is bad for air pollution and your pocket

Air Pollution – Idling school buses can pollute air in and around the bus. Exhaust from buses can also enter school buildings through air intakes, doors, and open windows. Diesel bus exhaust from excessive idling can be a health concern. Read more about health concerns.

Wasted Fuel and Money – Idling buses waste fuel and money. When idling, a typical school bus engine burns approximately half a gallon of fuel per hour. School districts that eliminate unnecessary idling can save significant dollars in fuel costs each year.

Engine Wear-and-Tear – School bus engines do not need to idle more than a few minutes to warm up. In fact extended idling causes engine damage. Engine manufacturers generally recommend no more than three to five minutes of idling.

  • Caterpillar Inc. cautions drivers to “… Avoid excess idling. If the vehicle is parked for more than five minutes, stop the engine. Excessive idling can cause carbon buildup and/or excessive idling can cause the engine to slobber. This is harmful to the engine.”
  • IC Corporation’s engine manual states that “…Excessive idling reduces fuel economy, and may decrease oil life.”
  • Cummins Inc. suggests idling for only three to five minutes before operating with a load.
No Idling Zone

No Idling Zone

Idling Myths and Facts

Myth:             It’s important to warm up the engine with a long idle period, especially in cold weather.

Fact: With today’s school bus engines, bus and engine manufacturers routinely suggest a warm up time of less than five minutes. In fact running an engine at low speed (idling) causes significantly more wear on internal parts compared to driving at regular speeds.

Myth:             It’s better for an engine to run at low speed (idling) than to run at regular speeds.

Fact: Running an engine at low speed causes twice the wear on internal parts compared to driving at regular speeds.

Myth:             The engine must be kept running in order to operate the school bus safety equipment (flashing lights, stop sign). It’s impossible to run this equipment off the internal circuitry of the bus because the battery will run down.

Fact: Safety equipment can be operated without the engine running through re-wired circuitry for up to an hour with no ill-effects on the electrical system of the bus.

Myth:             Idling is necessary to keep the cabin comfortable.

Fact: Depending on the weather, many buses will maintain a comfortable interior temperature for a while without idling. Idling is also not an efficient way to keep the cabin warm. Bus routes should be timed so children and drivers do not need to spend a lot of extra time on the bus when it is not en route, particularly in hot or cold weather. In addition, auxiliary heaters can be purchased and installed to keep the cabin comfortable.

Myth:             It’s better to just leave the engine idling because a “cold start” produces more pollution.

Fact: A recent EPA study found that the emission pulse measured after the school bus is restarted contains less carbon monoxide, nitrogen oxides, and other pollutants than if the school bus idled continuously over a 10-minute period. The analysis indicated that continuous idling for more than three minutes emitted more fine particle (soot) emissions than at restart.

Idling causes air pollution

Idling causes air pollution

So, with these facts (and not myths) on hand, contact your school bus company and have your school district to implement the following “No Idling Policy”.

School Bus Idling Policy

This policy applies to the operation of every district-owned and/or contracted school bus.


Diesel exhaust from idling school buses can accumulate in and around the bus and pose a health risk to children, drivers and the community at large. Exposure to diesel exhaust can cause lung damage and respiratory problems. Diesel exhaust also exacerbates asthma and existing allergies, and long-term exposure is thought to increase the risk of lung cancer. Idling buses also waste fuel and financial resources.


Eliminate all unnecessary idling by [district] school buses such that idling time is minimized in all aspects of school bus operation.


1. When school bus drivers arrive at loading or unloading areas to drop off or pick up passengers, they should turn off their buses as soon as possible to eliminate idling time and reduce harmful emissions. The school bus should not be restarted until it is ready to depart and there is a clear path to exit the pick-up area. Exceptions include conditions that would compromise passenger safety, such as:

  • Extreme weather conditions
  • Idling in traffic

2. At school bus depots, limit the idling time during early morning warm-up to what is recommended by the manufacturer (generally 3-5 minutes) in all but the coldest weather.

3. Buses should not idle while waiting for students during field trips, extracurricular activities or other events where students are transported off school grounds.

4. In colder weather, schools are directed to provide a space inside the school where bus drivers who arrive early can wait.

5. In colder weather, if the warmth of the bus is an issue, idling is to be at a very minimum and occur outside the school zone. The “warmed” bus is to enter the school zone as close to pick-up time as possible to maintain warmth and then shut down.

6. All service delivery vehicles shall turn off the engines while making deliveries to school buildings.

7. Transportation Operations staff are directed to revise bus schedules so that school bus caravanning can be avoided and the cleanest buses assigned to the longest routes.

8. All drivers shall receive a copy of this bulletin at the beginning of every school year.

Many school bus companies across the nation already have this policy in place. And why not? It saves them money. But your district might not have this policy. So, call your bus company today and give them the facts. And if they are still not convinced, go to the  EPA website on School Bus idling and obtain all the materials on how to approach your bus company to convince them. Imagine how much carbon dioxide emission we will be cutting from going into the air. You can even check the idling calculator  to see how much fuel your idling school bus is using.

We can keep our children healthy while saving the planet with just a phone call.