School bus

19th century

In the second half of the 19th century, many rural areas of the United States and Canada were served by one-room schools. For those students who lived beyond practical walking distance from school, transportation was facilitated in the form of the kid hack; at the time, "hack" was a term referring to certain types of horse-drawn carriages.^[3] Essentially re-purposed farm wagons, kid hacks were open to the elements, with little to no weather protection.

In 1892, Indiana-based Wayne Works (later Wayne Corporation) produced its first "school car"^[3][4] A purpose-built design, the school car was constructed with perimeter-mounted wooden bench seats and a roof (the sides remained open).^[3] As a horse-drawn wagon, the school car was fitted with a rear entrance door (intended to avoid startling the horses while loading or unloading passengers); over a century later, the design remains in use (as an emergency exit).

In 1869, Massachusetts became the first state to add transportation to public education; by 1900, 16 other states would transport students to school.^[4]

1900–1930

Following the first decade of the 20th century, several developments would affect the design of the school bus and student transport. As vehicles evolved from horse-drawn to "horseless" propulsion on a wider basis, the wagon bodies of kid hacks and school cars were adapted to truck frames. While transitioning into purpose-built designs, a number of features from wagons were retained, including wood construction, perimeter bench seating, and rear entry doors. Weather protection remained minimal; some designs adopted a tarpaulin stretched above the passenger seating.

In 1915, International Harvester constructed its first school bus;^[4] today, its successor company Navistar still produces school bus cowled chassis.

In 1919, the usage of school buses became funded in all 48 U.S. states.^[4]

In 1927, Ford dealership owner A.L. Luce produced a bus body for a 1927 Ford Model T. The forerunner of the first Blue Bird school buses, steel was used to panel and frame the bus body; wood was relegated to a secondary material.^[5] While fitted with a roof, the primary weather protection of the Luce bus design included roll-up canvas side curtains.^[5]

1930s

During the 1930s, school buses saw advances in their design and production that remain in use to this day. To better adapt automotive chassis design, school bus entry doors were moved from the rear to the front curbside, becoming a door operated by the driver (to ease loading passengers and improve forward visibility). The rear entry door of the kid hacks were re-purposed (as an emergency exit).

Following the introduction of the steel-paneled 1927 Luce bus, school bus manufacturing began to transition towards all-steel construction. In 1930,^[3] both Superior and Wayne introduced all-steel school buses; the latter introduced safety glass windows for its bus body.

As school bus design paralleled the design of light to medium-duty commercial trucks of the time, the advent of forward-control trucks would have their own influence on school bus design. In an effort to gain extra seating capacity and visibility, Crown Coach built its own cabover school bus design from the ground up.^[6][7][8] Introduced in 1932, the Crown Supercoach seated up to 76 passengers, the highest-capacity school bus of the time.^[7]

As the 1930s progressed, flat-front school buses began to follow motorcoach design in styling as well as engineering, gradually adopting the term "transit-style" for their appearance. In 1940, the first mid-engined transit school bus was produced by Gillig in California.^[9]

1940s

During WWII school bus manufacturers converted to military production, manufacturing buses and license-built trucks for the military.^[3][4][5][6] Following the war, school bus operation would see a number of changes, following developments within education systems.

Following WWII and the rise of suburban growth in North America, demand for school busing increased outside of rural areas; in suburbs and larger urban areas, community design often made walking to school impractical beyond a certain distance from home (particularly as students progressed into high school). In all but the most isolated areas, one-room schools from the turn of the century had become phased out in favor of multi-grade schools introduced in urban areas. In another change, school districts shifted bus operation from buses operated by single individuals to district-owned fleets (operated by district employees).^[5]

1950s–1960s

From 1950 to 1982, the baby boomer generation was either in elementary or high school, leading to a significant increase in student populations across North America; this would be a factor that would directly influence school bus production for over three decades.

During the 1950s, as student populations began to grow, larger school buses began to enter production. To increase seating capacity (extra rows of seats), manufacturers began to produce bodies on heavier-duty truck chassis; transit-style school buses also grew in size. In 1954, the first diesel-engined school bus was introduced, with the first tandem-axle school bus in 1955 (a Crown Supercoach, expanding seating to 91 passengers).

To improve accessibility, at the end of the 1950s, manufacturers developed a curbside wheelchair lift option to transport wheelchair-using passengers. In modified form, the design remains in use today.

During the 1950s and 1960s, manufacturers also began to develop designs for small school buses, optimized for urban routes with crowded, narrow streets along with rural routes too isolated for a full-size bus. For this role, manufacturers initially began the use of yellow-painted utility vehicles such as the International Travelall and Chevrolet Suburban. As another alternative, manufacturers began use of passenger vans, such as the Chevrolet Van/GMC Handi-Van, Dodge A100, and Ford Econoline; along with yellow paint, these vehicles were fitted with red warning lights. While more maneuverable, automotive-based school buses did not offer the reinforced passenger compartment of a full-size school bus.

1970s

During the 1970s, school buses would undergo a number of design upgrades related to safety. While many changes were related to protecting passengers, others were intended to minimize the chances of traffic collisions. To decrease confusion over traffic priority (increasing safety around school bus stops), federal and state regulations were amended, requiring for many states/provinces to add amber warning lamps inboard of the red warning lamps. Similar to a yellow traffic light, the amber lights are activated before stopping (at 100–300 feet (30.5–91.4 m) distance), indicating to drivers that a school bus is about to stop and unload/load students. Adopted by a number of states during the mid-1970s, amber warning lights became nearly universal equipment on new school buses by the end of the 1980s. To supplement the additional warning lights and to help prevent drivers from passing a stopped school bus, a stop arm was added to nearly all school buses; connected to the wiring of the warning lights, the deployable stop arm extended during a bus stop with its own set of red flashing lights.

In the 1970s, school busing expanded further, under controversial reasons; a number of larger cities began to bus students in an effort to racially integrate schools. Out of necessity, the additional usage created further demand for bus production.

1980s–1990s

For school bus manufacturers, the 1980s marked a period of struggle, following a combination of factors. As the decade began, the end of the baby-boom generation had finished high school; with a decrease in student population growth, school bus manufacturing was left with a degree of overcapacity. Coupled with the recession economy of the early 1980s, the decline in demand for school bus production left several manufacturers in financial ruin. To better secure their future, during the 1990s, school bus manufacturers underwent a period of transition, with several ownership changes leading to joint ventures and alignments between body manufacturers and chassis suppliers.

In 1986, with the signing of the Commercial Motor Vehicle Safety Act, school bus drivers across the United States became required to acquire a commercial driver's license (CDL). While CDLs were issued by individual states, the federal CDL requirement ensured that drivers of all large vehicles (such as school buses) had a consistent training level.^[4]

In contrast to the 1970s focus on structural integrity, design advances during the 1980s and 1990s focused around the driver. In 1979 and 1980, International Harvester and Ford each introduced a new-generation bus chassis, with General Motors following suit in 1984. To increase driver visibility, updates in line with chassis redesigns shifted the bus driver upward, outward, and forward. To decrease driver distraction, interior controls were redesigned with improved ergonomics; automatic transmissions came into wider use, preventing the risk of stalling (in hazardous places such as intersections or railroad crossings). Initially introduced during the late 1960s, crossview mirrors came into universal use, improving the view of the blind spots in front of the bus while loading or unloading. To supplement the rear emergency door in an evacuation, manufacturers introduced additional emergency exits during the 1980s, including roof-mounted escape hatches and outward-opening exit windows. Side-mounted exit doors (originally introduced on rear-engine buses), became offered on front-engine and conventional-body buses as a supplemental exit.

Alongside safety, body and chassis manufacturers sought to advance fuel economy of school buses. During the 1980s, diesel engines came into wide use in conventional and small school buses, gradually replacing gasoline-fueled engines. In 1987, International became the first chassis manufacturer to offer diesel engines exclusively, with Ford following suit in 1990.

While conventional-style buses remained the most widely produced full-size school bus, interest in forward visibility, higher seating capacity, and shorter turning radius led to a major expansion of market share of the transit-style configuration, coinciding with several design introductions in the late 1980s. Following the 1986 introduction of the Wayne Lifestar, the AmTran Genesis, Blue Bird TC/2000, and Thomas Saf-T-Liner MVP would prove far more successful.

During the 1990s, small school buses shifted further away from their van-conversion roots. In 1991, Girardin launched the MB-II, combining a single rear-wheel van chassis with a full cutaway bus body. Following the 1992 redesign of the Ford E-Series and the 1997 launch of Chevrolet Express/GMC Savana cutaway chassis, manufacturers followed suit, developing bodies to optimize loading-zone visibility. As manufacturers universally adopted cutaway bodies for single rear-wheel buses, the use of the Dodge Ram Van chassis was phased out. By 2005 the United States government banned the use of 15-passenger vans for student transport, leading to the introduction of Multi-Function School Activity Buses (MFSAB). To better protect passengers, MFSABs share the body structure and compartmentalized seating layout of school buses. Not intended (nor allowed) for uses requiring traffic priority, they are not fitted with school bus warning lights or stop arms (nor are they painted school bus yellow).

2000–present

The beginning of the 21st century would introduce extensive changes to the production of school buses. Though vehicle assembly saw few direct changes, manufacturer consolidation and industry contraction effectively ended the practice of customers selecting body and chassis manufacturers independently. While the aspect of customer choice was largely ended (as a result of corporate ownership and supply agreements), decreased complexity paved the way for new product innovations previously thought impossible. During the 2010s, while diesel engines have remained the primary source of power, manufacturers expanded the availability of alternative-fuel vehicles, including CNG, propane, gasoline, and electric-power buses.

At the beginning of the 2000s, manufacturers introduced a new generation of conventional-style school buses, coinciding with the redesign of several medium-duty truck lines. While Ford and General Motors shifted bus production to cutaway chassis, Freightliner and International released new cowled chassis in 2004 and 2005, respectively. In 2003, Blue Bird introduced the Vision conventional; in line with its transit-style buses, the Vision utilized a proprietary chassis (rather than a design from a medium-duty truck). In 2004, Thomas introduced the Saf-T-Liner C2 (derived from the Freightliner M2), with the body designed alongside its chassis (allowing the use of the production Freightliner dashboard). A trait of both the Vision and C2 (over their predecessors) is improved loading-zone visibility; both vehicles adopted highly sloped hoods and extra glass around the entry door. In 2005, IC introduced a redesigned CE-series to fit the International 3300 chassis; to improve visibility, the windshield was redesigned (eliminating the center post).

Between 2004 and 2008,^[17] Advanced Energy, an NC based non-profit created by the NC Utilities Commission begun an effort to move to plug-in hybrid school buses. A business^[18] and technical^[19] feasibility proved the benefits, and in 2006, 20 districts awarded a contract facilitated by Advanced Energy to IC Bus to produce the buses. Although the buses produced significant benefits,^[20] the buses were slowly discontinued when the hybrid system manufacture Enova faded into financial challenges.

In 2011, Lion Bus (renamed Lion Electric Company) of Saint-Jérôme, Quebec was founded, marking the first entry into the segment in over 20 years by a full-size bus manufacturer. Using a chassis supplied by Spartan Motors,^[21] Lion produces conventional-style school buses, its design features several firsts for school bus production. Along with a 102-inch body width, to resist corrosion, Lion uses composite body panels in place of steel. In 2015, Lion introduced the eLion, the first mass-produced school bus with a fully electric powertrain.

Small school buses have undergone few fundamental changes to their designs during the 2000s, though the Type B configuration has largely been retired from production. Following the 1998 sale of the General Motors P-chassis to Navistar subsidiary Workhorse, the design began to be phased out in favor of higher-capacity Type A buses. In 2006, IC introduced the BE200 as its first small school bus; a fully cowled Type B, the BE200 shared much of its body with the CE (on a lower-profile chassis). In 2010, IC introduced the AE-series, a cutaway-cab school bus (derived from the International TerraStar). In 2015, the Ford Transit cutaway chassis was introduced (alongside the long-running E350/450); initially sold with a Micro Bird body, the Transit has been offered through several manufacturers. In 2018, the first bus derived from the Ram ProMaster cutaway chassis was introduced; Collins Bus introduced the Collins Low Floor, the first low-floor school bus (of any configuration).

Types

There are four types of school buses produced by manufacturers in North America.^[1] The smallest school buses are designated Type A (short bus); a larger format (bodied on bare front-engine chassis) are designated Type B buses. Large school buses include Type C (bodied on cowled medium-duty truck chassis) and Type D (bodied on bare "forward control" or "pusher" chassis). Type C buses are the most common design, while Type D buses are the largest vehicles.

All school buses are of single deck design with step entry. In the United States and Canada, bus bodies are restricted to a maximum width of 102 in (2.59 m) and a maximum length of 45 ft (13.7 m).^[31][32] Seating capacity is affected by both body length and operator specifications, with the largest designs seating up to 90 passengers.

Other formats

In both public and private education systems, other types of school buses are used for purposes of student transport outside of regular route service. Along with their usage, these buses are distinguished from regular yellow school buses by their exterior design.

An "activity bus" is a school bus used for providing transportation for students. In place of home to school route service, an activity bus is primarily used for the purpose for transportation related to extracurricular activities. Depending on individual state/provincial regulations, the bus used for this purpose can either be a regular yellow school bus or a dedicated unit for this purpose. Dedicated activity buses, while not painted yellow, are fitted with the similar interiors as well as the same traffic control devices for dropping off students (at other schools); conversely, it cannot be used in regular route service.

A Multi-Function School Activity Bus (MFSAB) is a bus intended for use in both the private sector and the educational system. While sharing a body structure with a school bus, an MFSAB is not designed for use in route service, as it is not fitted with traffic control devices (i.e., red warning lights, stop arm) nor is it painted school bus yellow.^[33] Within the educational system, the design is primarily used for extracurricular activities requiring bus transportation; in the private sector, the MFSAB is intended as a replacement for 15-passenger vans (no longer legal for child transport in either the public or private sector).^[34] Many examples are derived from Type A buses (with derivatives of full-size school buses also offered).

Features

Livery

To specifically identify them as such, purpose-built school buses are painted a specific shade of yellow, designed to optimize their visibility for other drivers. In addition to "School Bus" signage in the front and rear above the window line, school buses are labeled with the name of the operator (school district or bus contractor) and an identification number.

Yellow color

Main article: School bus yellow

Yellow was adopted as the standard color for North American school buses in 1939. In April of that year, rural education specialist Frank W. Cyr organized a national conference at Columbia University to establish production standards for school buses, including a standard exterior color. The color which became known as "school bus yellow" was selected because black lettering on that specific hue was easiest to see in the semi-darkness of early morning and late afternoon. Officially, school bus yellow was designated "National School Bus Chrome"; following the removal of lead from the pigment, it was renamed "National School Bus Glossy Yellow".

Outside the United States and Canada, the association of yellow with school buses has led to its use on school-use buses around the world (although not necessarily required by government specification). Some areas establishing school transport services have conducted evaluations of American yellow-style school buses;^[35] to better suit local climate conditions, other governments have established their own color requirements, favoring other high-visibility colors (such as white or orange^[12][36]).

Retroreflective markings

While its yellow exterior makes it more conspicuous than other vehicles, a school bus can remain hard to see in some low-visibility conditions, including sunrise or sunset, poor weather (all seasons), and in rural areas. To further improve their visibility (to other vehicles), many state and provincial governments (for example, Colorado)^[37] require the use of yellow reflective tape on school buses. Marking the length, width, height, and in some cases, identifying the bus as a school bus, reflective tape makes the vehicle easier to see in low light, also marking all emergency exits (so rescue personnel can quickly find them in darkness).^[38] Other requirements include reflective "School Bus" lettering (or the use of a front-lighted sign).

The equivalent requirement in Canada is almost identical; the only difference is that red cannot be used as a retroreflective color.

Safety devices

To comply with federal and state requirements, school buses are equipped with a number of safety devices to prevent accidents and injuries and for the purposes of security.

Mirror systems

When driving and when loading/unloading students, a key priority for a school bus driver is maintaining proper sightlines around their vehicle; the blind spots formed by the school bus can be a significant risk to bus drivers and traffic as well as pedestrians.

In the United States, approximately 2⁄3 of students killed outside of the school bus are not struck by other vehicles, but by their own bus.^[39] To combat this problem, school buses are specified with sophisticated and comprehensive mirror systems. In redesigns of school bus bodies, driver visibility and overall sightlines have become important considerations. In comparison to school buses from the 1980s, school buses from the 2000s have much larger windscreens and fewer and/or smaller blind spots.

Emergency exits

For the purposes of evacuation, school buses are equipped with a minimum of at least one emergency exit (in addition to the main entry door). The rear-mounted emergency exit door is a design feature adopted from horse-drawn wagons (the entrance was rear-mounted to avoid disturbing the horses); in rear-engine school buses, the door is replaced by an exit window mounted above the engine compartment (supplemented by a side-mounted exit door). Additional exits may be located in the roof (roof hatches), window exits, and/or side emergency exit doors. All are opened by the use of quick-release latches which activate an alarm.

The number of emergency exits in a school bus is dependent on its seating capacity and also varies by individual state/provincial requirements. The most currently installed is eight on school buses in Kentucky. Buses that are owned or used by Kentucky school districts require, in addition to the main entry door, a rear exit door (or window, for rear-engine buses), a left-side exit door, four exit windows (two on each side), and two roof-mounted exit hatches. The current Kentucky standards were enacted after 27 people died in the Carrolton bus collision on May 14, 1988, in which a former school bus that was converted into a church bus was hit head on by a drunk driver.

Video surveillance

Since the 1990s, video cameras have become common equipment installed inside school buses. As recording technology has transitioned from VHS to digital cameras, school buses have adopted multiple-camera systems, providing surveillance from multiple vantage points.

While primarily used to monitor and record passenger behavior, video cameras have also been used in the investigation of accidents involving school buses. On March 28, 2000, a Murray County, Georgia, school bus was hit by a CSX freight train at an unsignaled railroad crossing; three children were killed. The bus driver claimed to have stopped and looked for approaching trains before proceeding across the tracks, as is required by law, but the onboard camera recorded that the bus had in fact not stopped and had the AM/FM radio playing.^[40]

In the 2010s, exterior-mounted cameras synchronized with the stop arms have come into use. The cameras photograph vehicles that illegally pass the bus when its stop arm and warning lights are in use (thus committing a moving violation).

Restraint systems

In contrast to cars and other light-duty passenger vehicles, school buses are not typically equipped with active restraint systems, such as seat belts; whether seat belts should be a requirement has been a topic of controversy.^[41] Since the 1970s, school buses have used the concept of compartmentalization as a passive restraint system^[42] during the late 2000s and 2010s, seatbelt design transitioned, with 3-point restraints replacing lap belts.

As of 2015, seatbelts are a requirement in at least five states:^[43] California, Florida, New Jersey, New York, and Texas; Canada does not require their installation (at the provincial level).^[44] Of the states that equip buses with two-point lap seat belts (Florida, Louisiana, New Jersey and New York), only New Jersey requires seat belt usage by riders.^[45] In other states, it is up to the district or operator whether to require riders to use them or not.

Passive restraints (compartmentalization)

According to the National Highway Transportation Association (NHTSA), studies completed previously on school buses showed that due to their size and heaviness, school buses did not require that safety belts be in place. Information gathered in previous studies showed that a size of a bus, combined with the design of the seat and the material in the space between the seats themselves, showed that there was no need for safety belts on a school bus. A bus is larger and heavier than a normal size passenger vehicle and could distribute the force of the crash evenly. Combined with the space between the seats as well as the design prevented serious injuries from happening. This attribute, does not carry over to a small bus due to its lesser size; buses with a GVWR under 10,000 pounds are required to have safety belts.^[46]

However, recent accidents involving school buses that have caused serious (if not fatal) injuries have caused the National Transportation Safety Board to conduct new tests to check the legitimacy of this continued practice. After completing these tests due to bus accidents in 2016, they have recommended that new buses being built need to have both a lap and shoulder harness in place. They have also recommended that 42 states add seat belts as a requirement. There are some states that have already added the lap belt. This study made the NTSB recommend adding shoulder harnesses to those states that already have a lap belt in place.^[47]

In 1967 and 1972, as part of an effort to improve crash protection in school buses, UCLA researchers played a role in the future of school bus interior design. Using the metal-backed seats then in use as a means of comparison, several new seat designs were researched in crash testing. In its conclusion, the UCLA researchers found that the safest design was a 28-inch high padded seatback spaced a maximum of 24 inches apart, using the concept of compartmentalization as a passive restraint.^[42] While the UCLA researchers found the compartmentalized seats to be the safest design, they found active restraints (such as seatbelts) to be next in terms of importance of passenger safety.^[42] In 1977, FMVSS 222 mandated a change to compartmentalized seats, though the height requirement was lowered to 24 inches.^[48] According to the NTSB, the main disadvantage of passive-restraint seats is its lack of protection in side-impact collisions (with larger vehicles) and rollover situations.^[42] Though by design, students are protected front to back by compartmentalization, it allows the potential for ejection in other crash situations (however rare).^[42]

Active restraints (seatbelts)

Federal Motor Vehicle Safety Standard (FMVSS) 222 was introduced in 1977, requiring passive restraints and more stringent structural integrity standards; as part of the legislation, seatbelts were exempted from school buses with a gross vehicle weight (GVWR) exceeding 10,000 pounds.

In 1987, New York became the first state to require seatbelts on full-size school buses (raising the seat height to 28 inches); the requirement did not mandate their use.^[49] In 1992, New Jersey followed suit, becoming the first state to require their use,^[49] remaining the only state to do so. Outside of North America, Great Britain mandated seatbelts in 1995 for minibuses used in student transportation.^[49] In 2004, California became the first state to require 3-point seatbelts (on small buses; large buses, 2005^[49]), with Texas becoming the second in 2010.^[49]

In 2011, FMVSS 222 was revised to improve occupant protection in small (Type A) school buses. Along with requiring 3-point restraints (in place of lap belts), the revision created design standards for their use in full-size school buses.^[49] While previously reducing seating capacity by up to one-third, NHTSA recognized new technology that allows using seatbelts for either three small (elementary-age) children or two larger children (high-school age) per seat.^[48][50] In October 2013, the National Association of State Directors of Pupil Transportation Services (NASDPTS) most recently stated at their annual transportation conference (NAPT) that they now fully support three-point lap-shoulder seat belts on school buses.^[51]

CBC Television's The Fifth Estate has been critical of a 1984 Transport Canada study, a crash test of a school bus colliding head-on that suggested that seat belts (at the time, which were two-point lap belts) would interfere with the compartmentalization passive safety system. This had become "the most widely cited study" in North America, according to U.S. regulators, and was frequently quoted for decades by school boards and bus manufacturers across the continent as a reason not to install seat belts. Transport Canada has stuck to its stance against installing seat belts on school buses, despite numerous newer studies and actual accidents showing that compartmentalization could not protect against side impacts, rollovers, and being rear-ended; which would have been avoided by implementing three-point seat belts that would have kept occupants from being thrown from their seats.^[52][53]

Production (North America)

In the United States and Canada, school buses are currently produced by nine different manufacturers. Four of them—Collins Industries, Starcraft Bus, Trans Tech, and Van Con — specialize exclusively in small buses. Thomas Built Buses and Blue Bird Corporation (the latter, through its Micro Bird joint venture with Girardin)—produce both small and large buses. IC Bus and Lion Electric produce full-size buses exclusively.

During the 20th century, Canada was home to satellite facilities of several U.S. firms (Blue Bird, Thomas, Wayne), exporting production across North America, with other production imported from the United States. Domestically, Corbeil manufactured full-size and small school buses (1985–2007) and Girardin produced small buses. In 2011, Lion Bus (today, Lion Electric Company/La Compagnie Électrique Lion) was founded as a Quebec-based manufacturer of full-size buses, shifting development to fully-electric vehicles.

Licensing

School bus drivers in the United States are required to hold a commercial driver's license (CDL). Full-size school buses are generally considered Class B vehicles; most van-based school buses are considered Class C vehicles. In addition to a standard P (passenger) endorsement, school bus drivers must acquire a separate S (school bus) endorsement; along with a written and driving test, the endorsement requires a background check and sex offender registry check.

Loading and unloading

Coinciding with their seating configuration, school buses have a higher seating capacity than buses of a similar length; a typical full-size school bus can carry from 66 to 90 . In contrast to a transit bus, school buses are equipped with a single entry door at the front of the bus. Several configurations of entry doors are used on school buses, including center-hinged (jack-knife) and outward-opening. Prior to the 2000s, doors operated manually by the driver were the most common, with air or electric-assist becoming nearly universal in current vehicles.

School bus routes are designed with multiple bus stops, allowing for the loading (unloading) of several students at a time; the stop at school is the only time that the bus loads (unloads) passengers at once.

To inhibit pedestrians from walking into the blind spot created by the hood (or lower bodywork, on Type D buses), crossing arms are safety devices that extend outward from the front bumper when the bus door is open for loading or unloading.^[58] By design, these force passengers to walk forward several feet forward of the bus (into the view of the driver) before they can cross the road in front of the bus.

In the past, handrails in the entry way posed a potential risk for to students; as passengers exited a bus, items such as drawstrings or other loose clothing could be caught if the driver was unaware and pulled away with the student caught in the door. To minimize this risk, school bus manufacturers have redesigned handrails and equipment in the stepwell area. In its School Bus Handrail Handbook, the NHTSA described a simple test procedure for identifying unsafe stepwell handrails.^[59]

Warning lights and stop arms

Around 1946, the first system of traffic warning signal lights on school buses was used in Virginia, consisting of a pair of sealed beam lights.^{[citation needed]} Instead of colorless glass lenses (similar to car headlamps), the warning lamps utilized red lenses. A motorized rotary switch applied power alternately to the red lights mounted at the left and right of the front and rear of the bus, creating a wig-wag effect. Activation was typically through a mechanical switch attached to the door control. However, on some buses (such as Gillig's Transit Coach models and the Kenworth-Pacific School Coach) activation of the roof warning lamp system was through the use of a pressure-sensitive switch on a manually controlled stop paddle lever located to the left of the driver's seat below the window. Whenever the pressure was relieved by extending the stop paddle, the electric current was activated to the relay. In the 1950s, plastic lenses were developed for the warning lenses, though the warning lights (with colorless glass lenses) used sealed-beam lamps into the mid-2000s, when light-emitting diodes (LEDs) came into use.

The warning lamps initially used for school buses consisted of four red warning lights. With the adoption of FMVSS 108 in January 1968, four additional lights, termed advance warning lights, were gradually added to school buses; these were amber in color and mounted inboard of the red warning lights.^[60] Intended to signal an upcoming stop to drivers, as the entry door was opened at the stop, they were wired to be overridden by the red lights and the stop sign.^[60] Although red & amber systems were adopted by many states and provinces during the 1970s and 1980s, the all-red systems remain in use by some locales such as Saskatchewan and Ontario, Canada, older buses from California, as well as on buses built in Wisconsin before 2005.^[61]

The Ontario School Bus Association has challenged the effectiveness of Ontario's all-red 8-light warning system, citing that the use of red for both advance and stop warning signals is subject to driver misinterpretation.^[62] The Association claims that many motorists only have a vague understanding of Ontario's school bus stopping laws and that few drivers know that it is legal to pass a school bus with its inner (advance) warning lights actuated. Transport Canada's Transport Development Centre compared the effectiveness of the all-red system to the amber-red system and found that drivers are 21% more likely to safely pass a school bus when presented with amber advance signals instead of red signals.^[63] Transport Canada states that amber advance signals are proven to be slightly superior to red signals and recommends that all-red warning signals be replaced by the eight-lamp system in the shortest period possible.^[63] After the issue had received media attention, a petition has been signed to make the switch from the all-red to amber advance lights on Ontario school busses.^[64][65] The Ministry of Ontario of Transportation (MTO) has not yet provided any plan or timeline for the change.

To aid visibility of the bus in inclement weather, school districts and school bus operators add flashing strobe lights to the roof of the bus. Some states (for example, Illinois)^[66] require strobe lights as part of their local specifications.

During the early 1950s, states began to specify a mechanical stop signal arm which the driver would deploy from the left side of the bus to warn traffic of a stop in progress. The portion of the stop arm protruding in front of traffic was initially a trapezoidal shape with stop painted on it. The U.S. National Highway Traffic Safety Administration's Federal Motor Vehicle Safety Standard No. 131 regulates the specifications of the stop arm as a double-faced regulation octagonal red stop sign at least 45 cm (17.7 in) across, with white border and uppercase legend. It must be retroreflective and/or equipped with alternately flashing red lights. As an alternative, the stop legend itself may also flash; this is commonly achieved with red LEDs.^[67] FMVSS 131 stipulates that the stop signal arm be installed on the left side of the bus, and placed so that when it is extended, the arm is perpendicular to the side of the bus, with the top edge of the sign parallel to and within 6 inches (15 cm) of a horizontal plane tangent to the bottom edge of the first passenger window frame behind the driver's window, and that the vertical center of the stop signal arm must be no more than 9 inches (23 cm) from the side of the bus. One stop signal arm is required; a second may also be installed.^[67] The second stop arm, when it is present, is usually mounted near the rear of the bus, and is not permitted to bear a stop or any other legend on the side facing forward when deployed.^[67]

The Canadian standard, defined in Canada Motor Vehicle Safety Standard No. 131, is substantially identical to the U.S. standard.^[68] In Alberta and Saskatchewan, the use of stop signal arms is banned under traffic bylaws in multiple cities, citing that they provide a false sense of safety to students by encouraging jaywalking in front of the bus rather than safely crossing at an intersection. These bans have been the subject of public debate in cities such as Regina and Prince Albert.^{[69][70][71][72]}

Alternative fuels

Although diesel fuel is most commonly used in large school buses (and even in many smaller ones), alternative fuel systems such as LPG/propane and CNG have been developed to counter the emissions drawbacks that diesel and gasoline-fueled school buses pose to the public health and environment.

The use of propane as a fuel for school buses began in the 1970s, largely as a response to the 1970s energy crisis. Initially produced as conversions of gasoline engines (as both require spark ignition), propane fell out of favor in the 1980s as fuel prices stabilized, coupled with the expanded use of diesel engines. In the late 2000s, propane-fueled powertrains reentered production as emissions regulations began to negatively affect the performance of diesel engines. In 2009, Blue Bird Corporation introduced a version of the Blue Bird Vision powered by a LPG-fuel engine.^[77] As of 2018, three manufacturers offer a propane-fuel full-size school bus (Blue Bird, IC, and Thomas), along with Ford and General Motors Type A chassis.

Compressed natural gas was first introduced for school buses in the early 1990s (with Blue Bird building its first CNG bus in 1991 and Thomas building its first in 1993).^[77][78] As of 2018, CNG is offered by two full-size bus manufacturers (Blue Bird, Thomas) along with Ford and General Motors Type A chassis.^[77][79]

In a reversal from the 1990s, gasoline-fuel engines made a return to full-size school buses during the 2010s, with Blue Bird introducing a gasoline-fuel Vision for 2016. As of current production, Blue Bird and IC offer gasoline-fuel full-size buses; gasoline engines are standard equipment in Ford and General Motors Type A chassis. As an alternative, gasoline-fuel engines offer simpler emissions equipment (over diesel engines) and a widely available fuel infrastructure (a drawback of LPG/CNG vehicles).^[80]

Electric school buses

In theory, urban and suburban routes prove advantageous for the use of an electric bus; charging can be achieved before and after the bus is transporting students (when the bus is parked). In the early 1990s, several prototype models of battery-powered buses were developed as conversions of existing school buses; these were built primarily for research purposes.

During the 2000s, school bus electrification shifted towards the development of diesel-electric hybrid school buses. Intended as a means to minimize engine idling while loading/unloading passengers and increasing diesel fuel economy,^[81] hybrid school buses failed to gain widespread acceptance. A key factor in their market failure was their high price (nearly twice the price of a standard diesel school bus) and hybrid system complexity.^[82]

In the 2010s, school bus electrification shifted from hybrids to fully electric vehicles, with several vehicles entering production. Trans Tech introduced the 2011 eTrans prototype (based on the Smith Electric Newton cabover truck),^[83] later producing the 2014 SSTe, a derivative of the Ford E-450.^[84] The first full-size electric school bus was the Lion Bus eLion, introduced in 2015; as of 2018, over 150 examples have been produced.^[85]

During 2017 and 2018, several body manufacturers introduced prototypes of electric school buses, with electric versions of the Blue Bird All American, Blue Bird Vision, Micro Bird G5 (on Ford E450 chassis), IC CE-Series, and the Thomas Saf-T-Liner C2 previewing production vehicles. During 2018, Blue Bird, Thomas, and IC introduced prototypes of full-size school buses intended for production; Blue Bird intends to offer electric-power versions of its entire product line.^[86] LionC all-electric school bus

Walking and cycling 'buses'

Walking buses and bike bus (known as riding school bus for students) take their names and some of the principle of public transport in a group to travel to school for students under adult supervision.

School bus derivatives

Church use

Churches throughout the United States use buses to transport their congregants, both to church services and events. A wide variety of buses are owned by churches, depending on needs and affordability. Larger buses may often be derived from school buses (newly purchased or second-hand). Other churches often own minibuses, often equipped with wheelchair lifts. When school bus derivatives are used, church bus livery is dictated by federal regulations, which require the removal of "School Bus" lettering and the disabling/removal of stop arms/warning lights.^[2] In some states, School Bus Yellow must be painted over entirely.

In church use, transporting adults and/or children, traffic law does not give church buses traffic priority in most states (Alabama, Arkansas, Kentucky, Tennessee, and Virginia being the only states where a church bus can stop traffic with flashing red lights^[87]).

Uses of retired school buses

As of 2016, the average age of a school bus in the United States is 9.3 years.^[88] School buses can be retired from service due to a number of factors, including vehicle age or mileage, mechanical condition, emissions compliance, or any combination of these factors.^[88] In some states and provinces, school bus retirement is called for at specific age or mileage intervals, regardless of mechanical condition. In recent years, budget concerns in many publicly funded school districts have necessitated that school buses be kept in service longer.

When a school bus is retired from school use, it can see a wide variety of usage. While a majority are scrapped for parts and recycling (a requirement in some states), better-running examples are put up for sale as surplus vehicles. Second-hand school buses are sold to such entities as churches, resorts or summer camps; others are exported to Central America, South America, or elsewhere. Other examples of retired school buses are preserved and restored by collectors and bus enthusiasts; collectors and museums have an interest in older and rarer models. Additionally, restored school buses appear alongside other period vehicles in television and film.

When a school bus is sold for usage outside of student transport, NHTSA regulations require that its identification as a school bus be removed.^[2] To do so, all school bus lettering must be removed or covered while the exterior must be painted a color different than school bus yellow; the stop arm(s) and warning lamps must be removed or disabled.^[2]

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  1942 Gillig/Chevrolet in use as a tour bus
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  1946 Chevrolet school bus restored and customized
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  The "Gator Bus", a 1960s Wayne/Chevrolet school bus repurposed as a sign for an alligator park in Louisiana
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  1980s Crown Supercoach restored, painted to match the bus from A League of Their Own
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  Retired school bus (Blue Bird TC/2000) in use as a rafting shuttle

School bus export

Retired school buses from Canada and the United States are sometimes exported to Africa, Central America, South America, or elsewhere. Used as public transportation between communities, these buses are nicknamed "chicken buses" for both their crowded accommodation and the (occasional) transportation of livestock alongside passengers. To attract passengers (and fares), yellow buses are often repainted with flamboyant exterior color schemes and modified with chrome exterior trim.