|
Reduced Idling and other Smart Practices for School Bus Operations
Unnecessary school bus idling pollutes the air, wastes fuel, and causes excess engine wear. Fortunately, it's easy to implement practices that reduce school bus idling.
About
PDF Files
Save Money and Reduce Pollution
Actions to reduce idling
Technologies to reduce idling
Idling myths
Other smart practices for environmentally-friendly school bus operations
Resources and materials
Save Money and Reduce Pollution
- Air Pollution
Idling school buses can pollute air in and around the bus. Exhaust from buses at idle 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. Typical school bus engines burn about half a gallon of fuel per hour of idling. School districts that eliminate unnecessary idling can save significant dollars in fuel costs each year. Try the idling calculator to estimate fuel savings from reducing idling in your school bus fleet.
- 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 3-5 minutes of idling. Caterpillar, Incorporated 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 suggests idling for only 3 to 5 minutes before operating with a load.
Actions to Reduce Idling
- Consider an idling reduction program for your school or school district
A sample school bus idling policy is available on this website as a model. At a minimum the policy should state that:
- As a general rule buses should be moving whenever the engine is on. The engine should be turned off as soon as possible after arriving at loading or unloading areas. The school bus should not be restarted until it is ready to depart.
- Limit idling time during early morning warm up to what the manufacturer recommends (generally no more than five minutes).
Take advantage of existing print materials to publicize your program or create your own materials. Consider tip sheets and pledge cards for drivers, "no idling" signs and posters for posting on school grounds, magnets, and window stickers.
Train bus drivers to understand and follow the idling guidelines.
Arrange for a comfortable space to be provided inside each school building and/or bus depots where bus drivers can wait.
Consider technology options to help with cabin comfort, and extreme weather and equipment operation.
Remember to follow idling laws and guidelines in your State or community, where applicable.
- Summary of State Idling Regulations by California's Air Resources Board [ 30KB PDF ] .
- California's 2003 anti-idling regulation [ 17KB PDF ].
- Implement Your Idling Reduction Program
Spot-check loading and unloading areas, delivery areas and bus depots for adherence to the idling guidelines.
Recognize drivers who successfully reduce idling.
Technologies to Reduce Idling
School buses can be retrofitted with equipment that helps reduce idling. While some of this equipment is standard or optional on new buses, older buses most likely will not have it. Note: EPA provides this information only as an aid to fleet managers and others concerned with bus idling, and it should not be viewed as an endorsement of any particular technology or product.
- Heaters
Aftermarket auxiliary heaters can be used to warm up engines and passenger compartments in colder climates. This equipment runs off the school bus fuel tank or off electric outlets and includes a timer that can be programmed to automatically start the heating function. There are three types of heaters:
- Engine Block Pre-Heaters are used to heat the engine block for a warm start. Each block pre-heater uses only 1/2 cup of diesel fuel per hour as opposed to at least a half-gallon of fuel per hour of idling. Block engine pre-heaters cost approximately $1200 - $1500, installed. Some of the reported benefits of these heaters are lower emissions and fuel savings, longer engine oil life, less wear-and-tear on the engine, and relatively easy installation and maintenance. They can be used in remote yards or other situations where electrical block heaters are not practical or possible to install and can be started by a timer, thus potentially saving time that would have been used to start and idle the buses.
- Compartment/Engine Block Heaters warm up the engine block and passenger compartments simultaneously using an auxiliary heater. These heaters cost approximately $2300 - 2500 installed. The heaters use only 1 cup of fuel instead of the half-gallon of fuel needed to idle for an hour. These heaters are especially useful for nighttime -activity buses and buses that transport very young and/or special-needs children. In addition, the radiant heat keeps the windows from frosting or fogging, a safety concern.
- Electric Plug-in Block Heaters warm up the engine block by heating the engine coolant or oil. They are powered by electricity and are available in a range of voltages and watts, drawing between 1000 - 1500 watts per bus per hour. They include a timer that can automatically start or turn off the heater. A heater is mounted on the engine block of each bus and is plugged in when the bus is parked at the depot. Even in the coldest climates, engines will have a "warm start." Bus depots and garages can be designed or retrofitted to bring in the electrical service required. These heaters usually cost less than $100.00.
Auxiliary school bus heaters are available from the following companies:
- Overhead Flashing Lights and Other Safety Equipment can be run by re-wiring the circuitry in the bus (some newer buses already have circuitry wired this way). The master switch for the overhead red flashing lights should be wired off the battery-positive side of the body solenoid (not the ignition side) so that it will have power at all times, even with the key in the "off" position. The wire terminals from the overhead flashing lights unit should be connected so that the complete system works with the key off and the door open. Check with the manufacturer of the overhead unit for more information on re-wiring the circuitry.
Idling Myths
| |
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.
|
Other Smart Practices for Environmentally-Friendly School Bus Operations
There are a number of important practices beyond idling policy that school administrators and fleet managers can institute to reduce school bus emissions and minimize exposure to diesel exhaust.
- Maintenance
- It is important that proper maintenance procedures, as suggested by engine and bus manufacturers, be followed for all school bus fleets. The National Association of State Directors of Pupil Transportation Services suggests that: "...Like any motor vehicle, if quality and corrective engine and vehicle maintenance programs are conducted, school buses of any age will run cleaner." Read the entire statement by NASDPTS [21K PDF, 4 pages]. This includes making sure that the exhaust systems are intact and functioning properly.
- Fleet Operation and Planning
- Assign the cleanest buses in the fleet to the longest routes.
- Inform drivers that following other diesel vehicles too closely can contribute to higher concentrations of diesel exhaust inside and outside the bus. Encourage bus drivers not to "caravan."
- Arrange bus departure times so that buses do not queue up for lengthy periods.
- Encourage children to sit in the front of the bus if the bus is not full.
- Examine the lay-out of the loading areas for each school. Re-configure to reduce queuing and idling.
- Reduce Emissions from Other Vehicles On or Near School Property
Prohibit other vehicles from idling. For example:
- Advise parents to turn off their cars when waiting to pick up or drop off children. Either distribute flyers or post signs on school property.
- Prohibit delivery trucks from idling on school grounds. Advise delivery services of the no-idling policy and consider posting signs in delivery areas.
Make sure that indoor air intakes are not located near delivery areas. If they are, either change the configuration of the intake or change the delivery location, if possible. For more information on minimization of the entry of air pollution into school buildings, visit EPA's school design web site.
Resources and Materials
- Sample Idling Policies
A number of school districts, communities and organizations have written anti-idling policies. For five examples:
- Idling Calculator
Calculate fuel and dollar savings using our easy, interactive idling calculator.
- Idling materials available from other organizations, states and school districts
Posters, handouts, sample policy from Minnesota .
Notice to drivers, drivers' tip sheet, pledge card and other materials from New England States on the New England Asthma Regional Council's web site .
- Case Studies
Fleets that have re-wired their safety equipment so that it can be used without the engine on have not experienced problems with draining the battery or other issues. In a pilot study in New Brunswick, Canada, safety equipment was re-wired to the battery. No technical problems were observed and the practice of no-idling was initiated district-wide in May, 2002. Visit www.nb.lung.ca/schools/3000e/ehi_sbi_e.htm for more information.
Washington State has launched a "no idle" program on school grounds. Visit Washington State's web site for more information.
Read about a Canadian city's successful campaign to lower idling on school grounds at www5.mississauga.ca/idlefree/ for more information.
- Curriculum and Resources for Children
Sierra Club's curriculum for 3rd - 8th graders on school bus idling. .
- Applicable local and state laws and regulations regarding idling
Summary of State Idling Regulations by California's Air Resources Board [ 30KB PDF ] ..
- More information about lowering pollution on school grounds
EPA's Indoor Air Quality Tools for Schools Kit.
Canada's Natural Resources Idling Reduction program .
Washington State's "Dare to Care About the Air" Idling Reduction .
|
