Dangerous Noise Levels on School Buses?

Stephen Dawson, Inventor
 Stephen Dawson, inventor of the school bus noise alarm (prototype patent pending) drove a berry bus one summer, and was a coach and a schoolteacher for 31 years in Vancouver, Washington. He used the new invention in his classroom and obtained excellent results. He soon realized his safety device could also measure noise levels on the school buses. The device could be integrated into the bus camera, a two-way radio, or GPS system to provide a history of noise levels, as well as an alert when noise levels were too high. Dawson presents his thoughts in this article. Dawson is retired from full-time teaching and is working to educate the public and education and government officials on this long neglected nation-wide epidemic. In addition, he is also working on marketing the device with companies and/or partnering with research institutions and individuals to get the prototype engineered and on school buses.

Guest Article by Stephen Dawson, School Bus Drivers Against Noise and Other Issues That Compromise Safety

Federal law states that the interior of a school bus must not exceed 85 decibels. I believe this refers to noise generated by the school bus itself, not the students.

All school buses must meet noise level requirements that prevent passenger compartment noise levels from exceeding 85 decibels, consistent with the advice of the National Institute for Occupational Safety and Health to prevent hearing loss.

This is interesting because I drove a berry bus one summer, as well as road on athletic trip buses for years where noise levels easily exceeded the Federal safety level.

While working as a teacher, the noise in my classroom could reach intolerable levels, especially when students were working together in large groups. I would stop the class activities and calm the class before resuming.

I knew there was a lot of noise on school buses. I coached track and had about 70 students on the bus and the din on the bus would become very loud. Also, being in the educational environment, I would hear about incidents, etc. from time to time. It wasn't until I started researching the transport of students on school buses that I discovered there were such huge problems, that this was a nation-wide epidemic.

Various unscientific studies and expert testimony alike have concluded that students often use the noise on the school bus to mask serious misbehavior. While the noise on the bus increases, students can instigate things that won't be noticed by the driver or other students until it is too late.

I believe much misbehavior can stem from the loud noise levels on the bus. The behavior may be due to the increased noise level itself, causing some students to become aggressive. The noise also contributes to behavior issues ranging from playing around and goofing off (throwing items, spit wads, etc.) to more serious actions such as bullying and physical assaults. With all the noise and commotion going on in many school buses there are students who take advantage of the situation.

Regardless, there are no scientific noise pressure studies concerning the school buses. I could not find any studies from federal, state or local governments that measured the noise levels on school buses while students are on board. The Virginia Tech Transportation Institute/Transportation Research Board (VTTI/TRB) has proposed an immediate study of school bus noise levels over concerns that school bus environments may be at risk.

This is remarkable since there is ample evidence that high noise levels exist on many school buses based on bus drivers complaints, first hand experience, observation, incidents, accident reports, and bus videos. The noise levels can be very loud, but there are no specific measurements.

It is a likely that many school buses across our country are generating at least 85 decibels and more from the students' noise combined with the interior background noise of the bus itself. According to federal regulation, these sound pressure levels may be unsafe.

James Kraemer (now retired and the owner of this blog) drove school bus for over twenty years. After a few hours, driving some of the routes his ears were ringing and his hearing was dulled. “By the end of the day I was shouting in the office when discussing normal issues. At home my Mrs. complained I had the TV too loud.”

Kraemer commented at my forum that on many of our nation’s school buses the sound levels might exceed safe levels, after he used sound meters to randomly measure the noise on his buses and other buses over a period of several years.

To clarify, none of the studies Kraemer performed was scientific. His sound meters did not measure spikes, and is not as accurate as the more sophisticated measuring equipment that scientific study groups use. His meters could be off by 1 or 2 dBA +/-.

The dBA pressure alone does not define the noise hazard. Accumulated noise sources, noise spikes, distance from the sound source and the place of measurement plus exposure time all help determine the noise hazard. (~ Temple University Department of Civil/Environmental Engineering (USA), OHSA (USA), Workers’ Compensation Board of B.C. (Canada), Canadian Centre for Occupational Health & Safety, CCHHS (Canada), and The State of Queensland Workplace Health and Safety (Australia)

Kraemer recorded these sound pressure readings in various school bus environments at random over a period of several years:

  • An older smaller bb transit, front mounted 6-cyl diesel engine, with a leaking engine compartment seal, the engine-cooling fan not engaged, was over 100 dBA in the driver’s compartment area.
  • A similar older bb transit gave readings in the front passenger area of 88 dBA with loud students but a good engine compartment seal.
  • A front engine conventional Freightliner with an acoustical ceiling only in the driver’s area and included screaming kids gave readings reaching into the 90's dBA.
  • An old conventional style bus with a huge diesel V-8 reached 114 dBA in the driver’s area when climbing. With steady acceleration on the highway gave readings of over 100 dBA with no kids on board. When reported the bus was removed from service and sold.
  • A newer bb rear engine big transit with full acoustical ceilings from front to back and high seats was in the 73-80 dBA range @45 MPH while sitting in the rear seat and with no students on board. Adding loud students increased sound pressure to 88 dBA and higher on occasion.
Note: Upper 70’s can affect children with Autism and children with other noise sensory issues.

Neil Coppola, president of American Bus Video, has been operating businesses providing mobile digital recorders in the fleet markets for 24 years, with the last 15 concentrating in the school bus markets. He and I have discussed the issue of noise problems on school buses.

Coppola said, "As a person who is constantly involved reviewing bus video system video files, I can attest to the deafening volume of noise on some of the 450,000 buses that transport children to and from school daily."

He goes on to say, "During live testing of some of the products, we ride in the buses, and I am in awe of the drivers of these buses who can show such restraint and focus on the road in spite of the unbelievable noise that is constantly distracting their attention and focus. This poses a seriously high risk for those children."

This is an opinion from a person that has had first hand experience. I don't believe Mr. Coppola is exaggerating about the noise levels. Students' noise level on school buses become progressively louder as time progresses. As the noise becomes louder, students need to talk louder to be heard over the rising din around them. The noise begins to snowball and repeats the cycle again.

The effect noise can have on some riders and their school bus drivers are significant and well worth funding the proposed TRB study.

Stephen Dawson can be contacted at his Facebook page.

Note: The TRB study is currently a proposal. It is not funded at this point. Urgency/Priority/ According to the proposal: "Distraction while driving is becoming more and more of a problem on the roadway each day. Not much is known about the distraction issues in school bus driving scenarios and therefore should be a priority to investigate immediately."  ~ Investigating School Bus Driver Distraction 

I contacted TRB for more information. They referred me to the Sponsoring Committee:
ANB70, Truck and Bus Safety

School Bus Noise: Supporting docs and resources.

Noise on the School Bus: Dangerous on Many Levels - As anyone who’s ever been on a school bus before knows, the bus can get loud. Very loud. And as any driver of a school bus can tell you, the noise level is something that is often hard to control. These factors can add up to a situation that is potentially hazardous, in more ways than one.

Self-Monitoring Sound Meter - Self-monitoring 17" traffic light sound meter, to monitor noise levels in the classroom or other area. Can stand on its own or be wall mounted. Adjustable settings, AC or battery operation.

OSHA Orders Bronx Bus Company to Rehire Driver and Pay Nearly $60,000 in Back Wages and Legal Fees - NEW YORK -- 2005 - The U.S. Labor Department's Occupational Safety and Health Administration (OSHA) has ordered Kids Bus Service, Bronx, N.Y., to rehire a driver fired for refusing to operate a school bus under unsafe circumstances.


  1. British Busses are also very loud. The engine sounds on some exceed 86dB which after 20 minutes fatigues my ears. I have hyperacusis and only really noticed this since having this condition.

  2. so.... if the noise level from the bus itself (older, front engine, flat nose with the hump of death in the middle) above OSHA or DOT acceptable levels, is this an offense they will investigate?? How would someone go so far as to prove the noise level? are the hand held decibal meters acceptable? thanks in advance!!

  3. I am looking for help. I am in year 50 as a school bus driver. For 10 years or so I drive a flat nose with a front Cummins V555. The V8 diesel was right beside me under the 'dog house'. Revs went to 3890 rpm before shifting. I have severe tinitus and hearing loss, but I need to prove the noise level to the compensation department before they will pay for hearing aids. Does anyone know of decibel documentation that I could use?


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