School Transportation History

If the 18th century is considered the period of school transportation infancy and the 19th century is the period of the industry's adolescence, the 20th century saw the evolution of a fully developed, mature industry. The solidifying role of the various disciplines such as construction standards, national minimum standards guidelines, scheduling and routing, federal motor vehicle safety standards, special needs transportation, railroad grade crossing safety, state and federal government involvement, occupant protection and more, have had a profound effect on the industry.

Throughout the last 100 years, the industry provided more than an estimated 500 billion student rides as the ranks of students being transported swelled to nearly 55 percent of all K-12 students. As the 20th century drew to a close, the Yellow School Bus had replaced the Little Red Schoolhouse as the symbol of K-12 public education in the United States. There is scant indication that transportation by yellow school bus will diminish during the 21st century.

School Bus Types



The Type A school bus is one of seven vehicle types that can be manufactured to federal motor vehicle safety standards for school buses. Traditionally, it consists of a bus body constructed upon a cutaway front-section vehicle with a left side driver's door, designed for carrying more than 10 persons. This definition includes two classifications: Type A-I, with a Gross Vehicle Weight Rating (GVWR) of 10,000 pounds or less, and a Type A-2, with a GVWR of 10,000 pounds or more. However, the new AE Series introduced by IC Bus in the fall of 2010 is a fully-integrated Type A school bus body and chassis.Type A school buses meet all Federal Motor Vehicle Safety Standards for school buses. These buses have traditionally referred to as "the short bus," a negative connotation denoting the fact that many transport students with disabilties. But today, Type As are just a frequently used for regular route transportation, albeit that of a smaller busload of children to, say, a neighborhood school.

ic_200bThe Type B school bus consists of a bus body constructed and installed upon a front-section vehicle chassis, or stripped chassis, with a gross vehicle weight rating of more than 10,000 pounds, designed for carrying more than 10 persons. Part of the engine is beneath and/or behind the windshield and beside the driver's seat. The entrance door is behind the front wheels. Type B school buses meet all Federal Motor Vehicle Safety Standards for school buses. These buses, which are more rare on today's roads and are designed for specific school district needs, falls squarely between a Type A school bus and Type C school bus in size. 

type_cSort of. The Type C school bus, also known as a "conventional," is a body installed upon a flat-back cowl chassis with a gross vehicle weight rating of more than 10,000 pounds, designed for carrying more than 10 persons. All of the engine is in front of the windshield and the entrance door is behind the front wheels. Type C school buses meet all Federal Motor Vehicle Safety Standards for school buses. Type Cs are the traditional school buses depicted in movies and on TV shows and has become as synonymous with the U.S. public education system if not more so than the little red school house and the apple on the teacher's desk of yesteryear. Increasingly, these buses are also equipped with wheelchair lifts to accomodate students with disabilities. But, to be technical, the first school buses were called cowls, basically enclosed horsedrawn carriages that evolved into motorized vehicles in the early 20th century.

bus_bluebird_transitThis is the Type D school bus, a transit-style vehicle with its body installed upon a chassis, with the engine mounted in the front, midship, or rear with a gross vehicle weight rating of more than 10,000 pounds, and designed for carrying more than 10 persons. The engine may be behind the windshield and beside the driver's seat; it may be at the rear of the bus, behind the rear wheels; or midship between the front and rear axles. The entrance door is ahead of the front wheels.Type D school buses meet all Federal Motor Vehicle Safety Standards for school buses. [Editor's note: Type D school buses are referred to as RE for "rear-engine," and FE for "foward engine, or FC for "forward control" ]

Multifunction School Activity Bus, or MFSABYou're referring to the Multifunction School Activity Bus, or MFSAB, a vehicle sold for purposes that do not include transportation between home and school for K-12 students. Since they are not intended to be used for picking up or discharging students on public roadways, MFSABs are exempt from the traffic control requirements and devices - stop arm, flashing lights - designed to control traffic. While the MFSABs are exempt from the traffic control requirements, they are required to comply with all school bus crashworthiness standards, all other requirements in the school bus crash avoidance and conspicuity safety standards, and all post-crash school bus standards. Schools and school districts are specifically prohibited from using MFSABs to transport school children in regular route school bus transportation service. These buses are often used for activity and sports trips or for Head Start transportation.

apv_libertyAn Allowable Alternate Vehicle is a van that meets all federal school bus crashworthiness standards, but does not meet conspicuity regulations or traffic control standards, i.e. flashing red lights, school bus yellow paint and left side stop arm. These school vehicles secure passengers better than a regular van in the event of a rollover crash. Federal regulations for Head Start transportation require that local agencies bus students on these AAVs or an MFSAB.

metrovan_usbusMeanwhile, a school van is a regular van converted to full school bus specifications. Major alterations are made to the vehicle including cutting the roof off and welding in a full roll cage, along with dozens of other major alterations. When complete, the vehicle rides like a regular van, but meets the Federal Motor Vehicle Safety Standards for school buses.

large_pass_vanA non-conforming van is a vehicle which does not conform to the applicable Federal Motor Vehicle Safety Standards for school buses. Most 15-passenger vans are little more than cargo vehicles converted to passenger application. Most do not even have the basic safety features of traditional passenger vehicles.

Student Transportation Safety

There are more than 450,000 yellow school buses on U.S. roads and about 70,000 in Canada. The industry spends more than $15 billion annually, most in the form of reimbursement to school districts for state-supported transportation costs.

In the United States, about 25,000,000 children ride school buses to school, and then return home on school buses. That's about 55 percent of the K-12 population. When you multiply the daily ridership times the number of school days school buses provide the United States with an estimated 10 billion student rides annually.

In 1939, delegates to the first National Minimum Standards Conference wanted a uniform color so school buses would be recognized by the same color nationwide. A second consideration was cost since manufacturers charged additional for special colors. Plus, delegates concluded that for safety sake, yellow was easier to see in fog, rain, and other bad weather conditions.

National School Bus Chrome Yellow was first adopted at that conference. By the way, the conference was held at Teachers College, Columbia University, April 10-16, 1939. All 48 states, at the time, were represented, usually by someone from the state department of education. The group called itself the "National Council of Chief State School Officers," and H.E. Hendrix, State Superintendent of Public Instruction of Arizona, was the first president.

In 1974 the federal government approved Standard 17. In this standard, which has since been revised and is now a highway safety guideline, the federal government suggested that school buses should be painted National School Bus Chrome Yellow. That's when the states started to use yellow on all new buses. At present there is no federal law that requires school buses to be painted yellow. It is up to each state to do so. Some states, South Carolina for example, paint some of their school buses, in this case activity buses, white though the bulk of the state's fleet is painted school bus yellow.

Federal regulation does not specify the number of persons that can sit on a school bus seat. The school bus manufacturers determine the maximum seating capacity of a school bus. The manufacturers use this number, which is based on sitting three small elementary school age persons per typical 39-inch school bus seat, in the calculations for determining the gross vehicle weight rating and the number of emergency exits. School transportation providers generally determine the number of persons that they can safely fit into a school bus seat. Generally they fit three smaller elementary school age persons or two adult high school age persons into a typical 39 inch school bus seat.

The National Highway Traffic Safety Administration recommends that all passengers be seated entirely within the confines of the school bus seats while the bus is in motion. Federal motor vehicle safety standard No. 222, "School Bus Passenger Seating and Crash Protection" requires that the interior of large buses provide occupant protection so that children are protected without the need to buckle-up. Occupant crash protection is provided by a protective envelope consisting of strong, closely-spaced seats that have energy-absorbing seat backs. Persons not sitting or sitting partially outside of the school bus seats will not be afforded the occupant protection provided by the school bus seats. It should be noted that FMVSS No. 222 was revised in 2008 to include additional manufacturing guidelines to safely incorporate 3-point lap/shoulder belt restraints in school buses, and previously school bus seating manufacturers began producing and marketing flexible bench seats that can fit three smaller, elementary-age students per seat buckled up or two larger middle school to high school-age students. This solved the problem of losing passenger capacity on school buses that are equipped with seat belts.

The short answer is that small school buses do require seat belts; large school buses, with a few exceptions, don't. Seat belts are not required on larger buses because the U.S. Department of Transportation and others, including Transport Canada, have determined that compartmentalization is the preferred occupant protection system.

Here's the longer answer.

Small buses, that is those under 10,000 lbs., are required by federal law to carry seat belts, and NHTSA's 2008 update to FMVSS 207, 208, 210 and 220 set standards for mandatory 3-point lap/shoulder restraints on these smaller "Type A" school buses. That's because these smaller buses are judged to be closer in size to automobiles and light trucks, and the federal government requires a level of occupant protection similar to what it requires for automobiles and light trucks. However, the same is not required for large school buses for a wide variety of reasons. Large buses typically weight 23,000 lbs or more. NHTSA's same regulatory update said local school districts are the best equipped to decide whether the larger "Type C" and Type D school buses have the seat belts. If the answer is yes, the manufacturing guidelines for how to best install these restraints comes into play.

Compartmentalization is a passive occupant protection strategy unique to school buses. Student riders are surrounded by a compartment of energy absorbing material -- 4-inch-thick foam seats, seat frames that bend to absorb crash forces, and a vehicle designed to absorb energy. The idea is the crash forces will be dissipated or absorbed before they get to the student passengers. However, compartmentalization doesn't work as well in rollover crashes, hence one of the reasons for NHTSA's regulatory update on seat belts.

Compartmentalization is a passive strategy. It exists without any action required on the part of the children or extra supervision by the drivers.

The principle arguments in favor of mandating seat belts on large school buses include protection in side impact collisions, prevention of ejection in the event of rollover accidents, carryover value to adulthood of learning proper seat belt use as a child, and low cost to install. Check out our dedicated Seat Belt section that takes a closer look at this volatile subject. (Close the second window on your browser to return to this section.)

To date only five states, New York, New Jersey and Florida have mandated 2-point lap-shoulder belts belts on large school buses. California has enacted legislation that would require three-point occupant restraint systems on large buses starting July 2005. In addition, since February 1996, seat belts have been required on minibuses used in school transport in Great Britain.

According to the National Safety Council, school buses are the safest form of ground transportation. In fact they are about 40 times safer then the family car.

Yes, unfortunately they do. In an average year, about 25 school children are killed in school bus accidents. One third of these are struck by their own school bus in the loading/unloading zone, one third are struck by motorists who fail to stop for the school bus, and one third are killed as pedestrians approaching or departing the school bus stop. Very few are killed inside the bus. The most common fatality involving a school bus is to a motorist who hits the bus. There are about 120 Americans killed annually in this type of fatality.

There are three major sources: the National Safety Council, the National Highway Traffic Safety Administration, and the Kansas Department of Education. The NSC offers both fatality and injury data, though its data is based on projections and extrapolations. Through the Fatal Accident Reporting System, or FARS as it is known, the National Highway Traffic Safety Administration collects data on all highway fatalities--automobiles, trucks, buses, pedestrians, bicyclists, etc.--in the nation. The agency has very strict criteria a fatality must meet to be included in its database. For instance, from FARS we know that an average of 120 motorists are killed annually when their automobile runs into a school bus. That's the most common fatality related to school buses.

The annual School Bus Loading & Unloading Zone Survey by the Kansas Department of Education, published in December or early January, reports the number of fatal accidents in the so called "danger zone" around the school bus. The danger zone is defined as the area 10 feet in front of, behind, and to both sides of the school bus. The data shows that is where most of the school bus accidents and fatalities to school children occur. They are either run over by their own school bus or struck by a motorist passing the stopped school bus. This series of data goes back to 1968. It only tracks student fatalities outside the bus. It does not compile data about fatalities or injuries to students or drivers inside the bus. Nor does it track fatalities to motorists who may collide with a school bus, nor data about student lives saved through the use of seat belts. Efforts are currently underway to expand the survey to include injury data.

The principal sources of national injury information about school buses is the National Safety Council and the National Highway Traffic Safety Administration. Many states annually publish injury and fatality data also.

The NSC projects injury data nationwide based on accident reports submitted to it by state departments of education.

The American Academy of Pediatrics also has monitored the number of school bus injuries, but its data looks for all instances in which a child had to visit the emergency room after an incident on a bus. It's important to note that this analysis could include anything from a student fight to slipping on the bus stairwell when loading or unloading.

No one knows for sure how many court-ordered busing plans are--or were--in place. Not even the U.S. Department of Justice keeps track of this information. However, in its heyday, experts in the field estimated there were as many as 400 court-ordered busing plans. Busing for integration purposes still exists, but more commonly it is now being reversed. Urban centers such as Cleveland and Denver have totally eliminated court-ordered busing.

School buses are probably the most regulated segment of the transportation industry. That's probably due to the fact that they carry children, and parents care about their children.

The federal government only regulates the industry at the manufacturing level. Through a series of federal motor vehicle safety standards, Uncle Sam requires all school buses to be manufactured to stringent safety standards. But federal jurisdiction only prevails until the vehicle hits the road. Then it becomes a state responsibility, until the school bus crosses state lines on an activity trip. Then the Federal Motor Carrier Safety Administration has jurisdiction.

States nationwide have extensive school bus regulations, typically in their motor vehicle laws and also education laws. Again, no one knows for certain, but research by School Transportation News has uncovered more than 500 state laws governing school transportation. In addition, school districts, as public entities, typically have extensive policies governing their school bus operations. These policies reflect both federal and state laws.




Clean School Bus

The U.S. Energy Policy Act defines alternative fuels as: Clean Diesel, Liquefied Petroleum Gas (LPG), Compressed Natural Gas (CNG), Liquefied Natural Gas (LNG), Biodiesel (B20), Electricity, and Hydrogen. This page provides links and information on the four alternative fuels for school buses: Compressed Natural Gas, Clean Diesel a.k.a. Low Sulfur Diesel (also known as Ultra-Low Sulfur Diesel or ULSD), Propane, and a recent addition, Biodiesel.

Governmental vehicle emission standards began in 1959 in California. The federal government became involved eight years later as Congress passed the Air Quality Act of 1967, which designated air quality regions throughout the country and gave states the responsibility for adopting and enforcing pollution control standards in those regions. In 1970, President Richard Nixon brought those responsibilities under one umbrella with the establishment of the Environmental Protection Agency. Since then, the EPA has regulated diesel fuel emissions on an almost annual basis. The most recent updates have been in 2004, 2007 and 2010 aimed at drastically cutting oxides of nitrogen and particulate matter.

The current alternative fuels for diesel-powered school buses are compressed natural gas (CNG) and clean diesel, or as it is sometimes known as ultra-low sulfur diesel. Biodiesel which is made from vegetable oils, such as soybeans, or animal tallow, such as grease. It is usually blended with petroleum diesel, but can be used purely with certain engine modifications. In April 2002, Minnesota became the first state to mandate at least a 2 percent blend of biodiesel. CNG is a mixture of hydrocarbons, mainly methane, extracted from gas wells or crude oil. It must be stored in either a compressed gaseous state or in a liquefied state (LNG). Ultra-low sulfur fuel is "cleaned" as extra oxygen is added to the combustion air supply, which causes it to burn more completely, substantially reducing emissions. However, the extra oxygen will destroy conventional catalytic converters, so special engines are needed with clean diesel-compatible catalytic converters. In addition, sulfur is extracted by refiners during the cracking process. Efforts to introduce battery-powered electric buses in the late 1990s floundered due to battery problems. Since then, hybrid-electric buses have gained steam, but they remain generally cost-prohibitive. IC Bus produces hybrids using Enova drivetrains, and the companies hoped to produce 300 vehicles in 2009. Thomas Built Buses is also developing its own hybrid school bus. Collins Bus Corporation, manufacturer of the Collins Bus and Mid Bus Type A small school bus lines in the United States and Corbeil in Canada, announced in April 2009 that it would be offering a gasoline hybrid bus using an Azure Dynamics hybrid-electric drive train on a Ford E-350 chassis. Those buses were expected to be ready for market by the summer of 2009.

Each of the alternative has significantly lower emission levels than traditional diesel. The debate over which fuel reduces emissions the most is ongoing. See the National Biodiesel Board, Natural Gas Vehicle Coalition and BP for the specific claims of each. Biodiesel reduces PM and HC emissions, but it is similar to diesel fuel in NOx emissions. CNG consists of 90 percent methane. While methane is a more intense greenhouse gas than carbon dioxide, it is not a volatile organic compound, which combines with NOx and sunlight to form ground level ozone, and therefore contributes less to greenhouse gas formation. Ultra-low sulfur fuel contains approximately 90 percent less sulfur than regular diesel and releases 90 percent less sulfur dioxide emissions. A 2002 California Air Resources Board study found buses equipped with a diesel particulate filter running on low sulfur diesel fuel produced fewer PM and HC emissions than a CNG bus.

The U.S. General Accounting Office reported in 2000 that the high cost of purchase, operation and maintenance of alternative-fueled public transit buses is greater than the marginal improvements in air quality from alternative fuels. The report said CNG buses cost 15-25 percent more than diesel buses, not including the high maintenance and fuel costs. This matters little, however, as the EPA set stringent emission rules in December 2002 that will require a 97 percent decrease, from 500 parts per million to 15 ppm, in the sulfur content of diesel fuel for trucks and buses by 2007. Because of the heavy financial burden of this mandate, a bill before Congress would authorize a grant program to offset the purchase of alternative-fueled school buses. Both CNG and low sulfur diesel are included. The Department of Education would appropriate $40 million for fiscal year 2002, with per year increases of $10 million thereafter, to provide up to 10-15 percent of the purchase price of an alternative-fueled school bus. California created a program in 2000 to distribute $50 million to the state's 15 air quality management districts to fund the purchase of low-emission school buses.

Standard No. 2 diesel exhaust releases particulate matter (PM), nitrogen oxide (NOx) and hydrocarbons (HC), which contribute to air pollution, but determining the health effects in regard to children riding school buses depends upon whom you ask. Recent studies by the Natural Resource Defense Council, the Union of Concerned Scientists and Environment and Human Health claimed diesel exhaust was particularly harmful to children. The UCS study asserted that school buses emit as much soot in a year as 125 cars, while the EHH study said its research showed school bus exhaust levels 5 to 10 times higher, during short periods, than government standards. The NRDC study has been discredited as it tested only four older buses of a model no longer in use. Moreover, critics point out that UCS did not actually do any scientific tests, rather it conducted a national survey of diesel buses and extrapolated as to their pollution effects. In the EHH study, the "short periods" were mere 10 second intervals. By contrast, a regarded 2001 study by Fairfax County (Va.) Public Schools said the air on school buses "poses no health risks to students." To date, this is the only study countering adverse health claims by environmentalists.

Diesel fuel has a higher boiling range than gasoline. Since engines create power by converting fuel to heat, the higher boiling range allows diesel engines to provide more horsepower than gasoline engines. Diesel provides greater fuel efficiency than gasoline because of the increased energy produced. Diesel engines emit 40 percent less carbon dioxide than gasoline, and produce lower amounts of hydrocarbon and carbon monoxide.

The first diesel engine was built by German inventor Rudolf Diesel (1858 - 1913) in 1893. By 1898, diesel engines were widely used. Diesel demonstrated mechanical efficiency of his engine to be 75.6 percent. More commonly used steam engines achieved an efficiency of 10 percent or less. Diesel demonstrated his engine at the World Exhibition in Paris in 1900 using peanut oil as fuel.

Non-Conforming Vans

The federal Motor Vehicle Safety Act prohibits the sale to a school or the purchase by a school of a vehicle under the following circumstances:
1. The vehicle must be sold new;
2. The vehicle must have a capacity of greater than 10;
3. The vehicle must be used to transport pre-primary, primary or secondary students to and from school or school related activities; and
4. The vehicle must not meet federal school bus safety standards.

The reason is that when the school bus safety provision was added to the existing Motor Vehicle Safety Act, the only applicable vehicles covered by the original Act were those sold new. This made sense under the original Motor Vehicle Safety Act since it was not easy to mandate new safety standards retroactively. There is no question that as to the school bus safety features, this is a loophole in the federal law. However, in the course of investigating illegal van sales to schools, we found most involved sales of new vehicles.

Again, this is a feature of the Motor Vehicle Safety Act, which prohibits manufacturers and dealers from selling unsafe vehicles and does not make it illegal for a consumer to purchase such a vehicle. There is no question that this loophole has created an incentive by some schools to try to defeat the intent of the federal statute by trying to find a dealer willing to sell vans to schools. As the Strebler case indicated, however, the schools undertaking such a course of knowingly utilizing vehicles not meeting federal safety standards face potential liability under ordinary negligence theories unless their state specifically authorizes this use of such vehicles

Federal statute is the supreme law of the land and any sale by a dealer to a school is in violation of the federal statute, notwithstanding efforts by a state to make such transactions lawful. The primary effect of such statutes is to potentially defeat claims against schools utilizing these vehicles from grieving families in wrongful death cases or seriously injured children who have survived collisions in these unauthorized vehicles. States that don't comply can see a withholding of federal highway safety funds, similar to what happens when states don't enforce primary seat belt or drunk driving laws.

The law has not been firmly established on this issue, but it is likely that any institution carrying the name "school", "academy", "kindergarten", or other similar name will probably be subject to the statute. Moreover, any program which has sequenced instruction or promotes itself as teaching certain basic skills will also likely be considered to be a school.


No. In fact, comparable sized small school buses are required to have seat belts because they weigh less than 10,000 pounds. School buses, as indicated above, have markedly superior per road mile safety records than all other vehicles, regardless of the seat belt issue. In fact, school buses are designed with a "compartmentalization" concept, which keeps children within and near their seats by placing the seats forward to them very close and with significant interior padding and other safety features

Congress, in its wisdom, created special protections on nonconforming vans especially for children on their way to and from school and transported by their school district. This law has not been extended to protect others, and many safety experts say that Congress should look to address this issue, particularly for children transported by day care centers.

The initial cost of a 15 seater school bus is approximately $8,000.00 to $9,000.00 greater than a comparable sized van. However, the school bus has a significantly longer road life and is less expensive to maintain. Recent calculations have determined that the per road mile cost of a 15 seater school bus is actually cheaper than a comparable sized van.

Parents can transport kids on motorcycles to school or let them cross dangerous roads unsupervised, and no one would suggest schools can do this. Federal law expects higher levels of safety to be provided by school officials transporting school children to school or to school related activities.

There are three options for school transportation personnel:
1. You can inform all school officials attempting to purchase these nonconforming vans that such a sale violates the Motor Vehicle Safety Act and the seller is breaking the law. Moreover, the purchaser of such a vehicle faces potential liability under the common law of negligence should a child be injured or die in a collision in a nonconforming van. You may want to go on record about such unlawful sales because schools and school districts may be very reluctant to engage in such sales if they know that there is, in writing, concerns raised about these vehicles that might be disclosed later should some tragic event occur.
2. Any violation known can be reported confidentially to the National Highway Traffic Safety Administration. The contact person is Mr. Allen Kam in the Office of General Counsel, whose number is 202-366- 5248. Based upon recent new attention to this area by NHTSA, it is likely that any report will be promptly investigated and sanctions taken against the dealer who sells such a vehicle.
3. You may advise families who have children injured or killed in such vehicles of their potential legal rights to pursue damage claims against the parties who participated in the sale or purchase of nonconforming vans. In the final analysis, the threat of liability may be the most effective deterrent against the use of nonconforming vans to transport school children.

School Bus Seat Belts

Many parents are worried about the contradiction between the need to use seat belts and child passenger seats in automobiles and the lack of these safety devices in school buses, which don't require seat belts. One reason seat belts are not required on school buses is that the greater weight and mass of a school bus means that passengers are less vulnerable in a school bus than in an automobile, and they sit above the usual point of impact. Another is the school bus passengers are not seated near doors or large window openings, so they are not likely to be thrown from the vehicle. Protection from ejection is a primary function of automobile seat belts.

But the main reason is that school buses incorporate a passive restraint system called compartmentalization, which is designed to protect children without seat belts.

The term was coined in the late 1960s by researchers at UCLA. Broadly, the term compartmentalization. denotes a safety envelope or "compartment" around passengers in school buses. The idea is that if a crash occurs, the child may be thrown around within the compartment but the design of the seat compartment absorbs the crash forces and protects the child. However, the seats currently installed in school buses are different from those recommended by UCLA researchers. The seats they proposed were 8" higher, were more energy absorbing, and were equipped with a massive side arm at the aisle to complete the compartment.

Seat belts are not required in school buses over 10,000 lbs. gross vehicle weight rating (G.V.W.R.) because the federal government concluded from available research that compartmentalization is a better safety measure. Some of the key arguments favoring compartmentalization rather than seat belts are as follows:

Compartmentalization is more manageable. The protection exists and is in force without depending on any action by the children or any extra special supervision by drivers or monitors. Seat belts require discipline and supervision to keep them clean, unraveled, in use, and properly adjusted.

Compartmentalization works equally well for one, two or three students per seat during a frontal- or rear-impact crash. Today's 39-inch wide standard seats may contain three small children or two large ones or any combination in between. Arranging seat belts to properly handle any combination is difficult, if not impossible; the best known solution with seat belts is to restrict each seat to two students and two belts, which has the disadvantage of sharply reducing the carrying capacity of bus fleets.

Compartmentalization works whether students have fully developed abdominal areas or not. Conventional seat belts, which are lap restraints only, are not suitable for small children (under 8 years of age) whose abdominal area and bone structure are not adequately developed to take the force of a lap belt alone. They need the help of chest harnesses also, which adds to the complexity of a proper safety belt solution.

Compartmentalization, once it has done its energy absorbing job, leaves the student free to escape the bus. Seat belts could leave students strapped in, upside down, perhaps unconscious, in burning or flooding buses.

Compartmentalization is most affordable. Although not a part of the DOT reasoning, this is a factor to be considered. In evaluating the cost of seat belts, one should include the cost of retractors and chest restraints, also, since those appear to be needed. Even more important to cost projections is the probability that a seat belt solution will lead to two students per seat and greater spacing between seats, thereby requiring more buses for the same student load.

First of all, the National Highway Traffic Safety Administration mandated in the spring of 2009 that all small school buses manufactured as of October 2011 must be equipped with 3-point lap/shouler restraints. Previous NHTSA studies found that lap belts in school buses provide no additional occupant safety beyond compartmentalization provided by federally mandated high and padded seat backs. NHTSA also prefers the use of 3-point lap/shoulder restraint sytems similar to those mandated in passenger vehicles because they better protect passengers in collisions and rollovers. It found lap belts may increase abdominal and head injuries.

Now, assuming there a lap-belt requirement applied only to new buses, and that retrofitting would not be required, about 25,000 to 30,000 large buses would be equipped annually. That's how many large school buses are manufactured in a typical year. At an estimated cost of $1,500 to $3,000 per bus to install two-point lap belts, which is about 2 percent of the cost of a typical small $60,000 school bus. The additional cost to install two-point lap belts on all new large school buses would range between $37,500,000 to $60,000,000 annually. Historically it takes about 12 to 15 years to convert the entire fleet, though a small percentage of pre-1977 buses remain in service. During the transition, the total cost to install two point lap belts would range between $450,000,000 and $900,000,000, and this leaves aside annual maintenance and replacement costs. These costs increase to the tune of about $7,000 to $16,000 per bus for three-point lap/shoulder belts that require not only more material but stronger anchorage points and bus floors, according to school bus vehicle and school bus seat manufacturers. Thomas Built Buses says that it may cost up to $750 more per seat to install lap/shoulder belts than a bus that is not equipped with the restraint systems. One school bus contractor company in Connecticut has cited costs as high as $20,000 per bus to install lap/shoulder belts. Meanwhile, the National Highway Traffic Safety Administration reports the nationwide seat belt cost would be between “$183 and $252 million” for all school buses, and “save about 2 lives per year” and “prevent 1,900 crash injuries per year.”

Retrofitting assumes the underfloor of the bus is sound, and that's not necessarily the case. Road damage, rust and other weathering factors are known to weaken the underfloor after a couple of years. Since the seat which holds the seat belt is anchored to the floor, you can't be sure of the strength of the anchorage. Anyway, bus manufacturers have stated they won't assume any liability if their buses are retrofitted, and it is unlikely insurance companies will either.

Since NHTSA published its study on the Next Generation of Occupant Protection in School Buses, 3-point lap/shoulder occupant protection systems have become the preferred solution, mandated for small buses and optional for large buses effective September of 2011. C.E. White with its Student Safety Seat System, IMMI with its SafeGuard Flex Seat product line and M2K/Takata now offer 3-point systems that are fully compliant with all federal requirements and fit either three smaller children to a seat or two large middle school or high school students, resulting in virtually no reduction in capacity.

Maybe. But the problem is that no one knows for sure. Injury data is harder to come by, in large part because there is no standardized method to collect the data. Scarcely any two states use the same reporting criteria, so it is difficult to compare data with previous years' experience. Never-the-less, the National Safety Council surveys states annually for school bus injury information, but its data is not based on actual incidents. It is survey data. In its Jan. 18, 1998 broadcast CNN reported, based on its interpretation of information supplied by the National Safety Council, that injuries on school buses increased 94 percent over a recent 12-year period: 13,000 injuries nationwide in 1995-96 school year, up from 6,900 injuries in 1985.

A more exacting and reliable interpretation of injury data comes from General Estimating System (GES) of the National Highway Traffic Safety Administration. The GES is a companion database to the Fatal Accident Reporting Systems (FARS) which is based on police accident reports submitted to the U.S. Dept. of Transportation in a standardized reporting format by all police agencies nationwide. The GES is desinged to estimate accident and injury phenomen. Unlike the National Safety Council, which gather its school bus accident data by surveying state departments of education, the GES is based on statistically valid methodology. In late 1997, based on GES data of nearly 1,800 school bus crashes drawn from the FARS data base covering 1985 to 1994, stataticians from NHTSA found an average of 8,551 school bus injuries annually. Of these 96 percent were minor to moderate (bumps, bruises and scratches) while the remaining four percent were serious to critical. The American Academy of Pediatrics reported in 2007 that actual school bus injuries were three times as high as federal estimates. But it was an apples to oranges comparison. The federal estimates rely on actual crash reports while the AAP study gauged all emergency room visits by students over a three-year period that were tied to any school bus injury, such as those resulting from a crash, a student fight, slipping down on the stairwell, etc. It's also important to note that most school districts have a policy that all students engaged in a crash, whether it be serious or a minor fender bender, be transported to a hospital for evaluation.

The school bus seat manufacturers currently offer seats with seat belts systems that can accomodate both three and two passengers based on age, height and weight. These are referred to as "flex" seats so as to not decrease passenger capacity, even when lap/shoulder seat belts are present. The rated capacity of a 39-inch wide passenger seat was devised many years ago by the committee then making recommendations to the National Minimum Standards for School Buses. In determining seating capacity of a bus, an allowable average rump width standard was established. Accordingly, 13-inch of rump width was suggested when a 3-3 seating plan was used. This works reasonably well for children through about the sixth grade. It absolutely doesn't work for junior high and high school students. Especially with the increase in tiered bell times for different grade levels, schools now have additional options for transporting their students.

The basic purpose in spacing school bus seats so closely is to "contain" the child in a cushioned compartment with a minimum amount of space between energy-absorbing surfaces.

After extensive research during the 1970's, the Department of Transportation and its agency, the National Highway Traffic Safety Administration (NHTSA), determined that the safest and most practical arrangement for school bus seating would be a "compartmentalization" concept. Accordingly, the new safety regulations that were effective for school buses manufactured on or after April 1, 1977, included this requirement among other improvements made that year.

Under the compartmentalization concept, seat backs in school buses are higher, wider and thicker than before. All metal surfaces are covered with foam padding. This structure must then meet rigid test requirements for bending and absorbing energy, such as would be required if a student's body were thrown against the padded back. In addition, the equivalent of a seat back, called a "barrier," is placed in front of the first row of seats at the front of the bus.

In addition to padding, today's seats also must have a steel inner structure that springs and bends forward to help absorb energy when a child is thrown against it. The steel frame must "give" just enough to absorb the child in the seat ahead. Also, of course, the seat is required to be anchored to the floor so strongly that it will not pull loose during this bending action. And the floor itself must be so strong that it will not be torn by the pulling action of the seat anchors during a crash.

Seats are spaced close together as another safety protection to ensure containment of children after a crash. If the seats are spaced too far apart, the student could be thrown too far before being cushioned and/or could be thrown outside the compartment altogether.

Current regulations require that seats are no more than 24-inches apart

Seat belts are required on small school buses under 10,000 lbs G.W.W.R. by FMVSS No. 222. The reason for requiring safety in small school buses is that these vehicles are closer in size and weight to passenger cars, light trucks and vans, and thus do not automatically afford the same protection of the heavier, larger school buses. Currently, the federal law requires two-point lap belts on these buses. Beginning in September 2011, all newly manufactured "Type A" school buses will be required to have three-point lap/shoulder belts. Meanwhile, a standard will also be implemented that gives guidance on how to best install lap/shoulder belts in larger conventional Type C and transit-style Type D school buses.

This regulation, titled School Bus Passenger Seating and Crash Protection, specifies occupant protection requirements for school bus passenger seating and restraining barriers. This standard provides increased protection to passengers through a range of engineering requirements collectively known as compartmentalization. This standard only applies to school buses and covers all styles of school bus. FMVSS 208 applies to automobiles.

According to bus manufacturers, adding seat belts and the attendant structural reinforcement at the time of manufacture adds about $10,000 to $15,000 to the cost of a new, 66- to 78-passenger school bus. Maintaining, repairing and replacing damaged belts can add $500 or more per bus to annual maintenance costs.

Retrofiting is a very controversial subject. Mainly because no one knows the condition of the outside of the bus floor. Is there any rust? Road damage? Can the floor of an older bus offer the strength needed for seatbelt equipped seats to meet FMVSS 222? Those questions, most knowledgeable experts agree that seat belts should not be added or retrofitted to an older school bus unless the bus was originally manufactured "seat belt ready." This means it was built with stronger seats and additional reinforcement in the structure of the bus, including the anchorages that hold the seat to the floor to withstand the added "loading" of belted passengers during a crash. The cost to retrofit has been estimated by one bus manufacturer to range between $2,700 to $3,400 for a 66- to 78-passenger school bus, to a cost estimated to range between $5,000 to $11,000 per bus by an agency of the New Hampshire state government.