Patent Publication Number: US-2023150584-A1

Title: Vehicle cab systems and methods

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application claims the benefit of and priority to U. S. Provisional Application No. 63/280,360, filed Nov. 17, 2021, the entire disclosure of which is hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     Vocational vehicles typically include a cab that may be coupled to components, such as a chassis or an implement. 
     SUMMARY OF THE INVENTION 
     At least one embodiment relates to a vehicle that includes a chassis coupled to a wheel and having a first portion and a second portion, and a cab supported by the first portion of the chassis. The cab includes a tunnel configured to receive at least partially receive the first portion of the chassis and a seat supported within an interior of the cab and having a seat support and a backrest. An uppermost surface of the tunnel is arranged at a tunnel height that is lower than a support height of the seat support. The vehicle further includes a body supported by the second portion of the chassis. The first portion of the chassis includes a frame extension or an inward-offset frame rail configuration and the second portion of the chassis comprises a first frame rail and a second frame rail. 
     Another embodiment relates to a vehicle that includes a chassis coupled to a wheel and having a first frame rail and a second frame rail, and a cab supported by a front portion of the chassis. The cab includes a tunnel protruding into an interior of the cab. The tunnel divides the cab into a first side and a second side, and the tunnel defines a lateral tunnel width that is greater than a width defined laterally between exteriors of the first frame rail and the second frame rail at the front portion of the chassis. The cab further includes a first seat within the interior of the cab and arranged on the first side of the cab, and a second seat within the interior of the cab and arranged on the second side of the cab. The vehicle further includes a body supported by a rear portion of the chassis. 
     Another embodiment relates to a vehicle that includes a chassis coupled to a wheel and having a front portion and a rear portion, and a cab supported by the front portion of the chassis. The cab includes a tunnel configured to receive at least part of the front portion of the chassis. The tunnel divides the cab into a first side and a second side. The cab further includes a first seat within the interior of the cab and arranged on the first side of the cab, and a multi-step entry arranged on the first side of the cab and including a first step and a second step. A height of the first step and a height of the second step are approximately equal. The vehicle further includes a body supported by the rear portion of the chassis. 
     This summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices or processes described herein will become apparent in the detailed description set forth herein, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which: 
         FIG.  1    is a left side view of a vehicle, according to an exemplary embodiment; 
         FIG.  2    is a perspective view of a chassis of the vehicle of  FIG.  1   , according to an exemplary embodiment; 
         FIG.  3    is a perspective view of the vehicle of  FIG.  1    configured as a refuse vehicle, according to an exemplary embodiment; 
         FIG.  4    is a perspective view of the vehicle of  FIG.  1    configured as a mixer vehicle, according to an exemplary embodiment; 
         FIG.  5    is a perspective view of the vehicle of  FIG.  1    configured as a fire fighting vehicle, according to an exemplary embodiment; 
         FIG.  6    is a left side view of the vehicle of  FIG.  1    configured as an airport fire fighting vehicle, according to an exemplary embodiment; 
         FIG.  7    is a perspective view of the vehicle of  FIG.  1    configured as a boom lift, according to an exemplary embodiment; 
         FIG.  8    is a perspective view of the vehicle of  FIG.  1    configured as a scissor lift, according to an exemplary embodiment; 
         FIG.  9 A  is a perspective view of a chassis of the vehicle of  FIG.  1   , according to an exemplary embodiment; 
         FIG.  9 B  is a perspective view of a chassis of the vehicle of  FIG.  1   , according to an exemplary embodiment; 
         FIG.  10    is a top view of an interior of a cab of the vehicle of  FIG.  1   , according to an exemplary embodiment; 
         FIG.  11    is a perspective view of the interior of the can of  FIG.  10   ; 
         FIG.  12    is a cross-sectional view of the interior of the cab of the vehicle of  FIG.  1   , according to an exemplary embodiment; 
         FIG.  13    is a side view of the interior of the cab of the vehicle of  FIG.  10   , according to an exemplary embodiment; 
         FIG.  14    is a side view of the interior of the cab of the vehicle of  FIG.  10   , according to an exemplary embodiment; and 
         FIG.  15    is a perspective view of the cab of the vehicle of  FIG.  1   , according to an exemplary embodiment 
     
    
    
     DETAILED DESCRIPTION 
     Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting. 
     According to an exemplary embodiment, a vocational vehicle (e.g., refuse trucks, mixing vehicles) includes a cab configured to house an operator and various systems and controls of the vocational vehicle. In some embodiments, the cab includes a tunnel that extends along a centerline of the cab. The tunnel protrudes into the interior of the cab and defines a recess on the exterior of the cab to receive a support structure. In some embodiments, the support structure is a chassis. The chassis may include a front portion that is narrower than a rear portion, such that the front portion fits within the tunnel of the cab and supports the cab via the tunnel. In some embodiments, there are no other devices (e.g., an engine) disposed within the tunnel. This allows the tunnel to be lower and allows the cab to sit closer to the ground. 
     In some embodiments, the size of the tunnel is defined by the elevation and width of the chassis. A tunnel with a smaller width allows a seat inside the cab to be positioned further inboard within the cab. A shorter tunnel allows a top of the tunnel to be below where an arm of an operator would traditionally be. In such an embodiment, the seat can be disposed directly next to or even partially above the tunnel and still provide the operator with the necessary clearances. This allows the entire cab to be reduced in size (e.g., total volume) since the seats are disposed closer to the middle of the cab and the tunnel does not restrict operator clearances. 
     In another embodiment, the cab includes a multi-step entry. The multi-step entry may include a plurality of steps. In one embodiment, the multi-step entry includes stair-style steps, where each of the plurality of steps is substantially the same height. In an exemplary embodiment, a first step is 15 inches above a ground on which the vehicle travels and a second step is 15 inches above the first step. This allows for easier entry and exit for an operator of the vehicle. 
     Incorporating the elements of the cab described herein allows the overall size of the cab to decrease and improves the ergonomics of the vocational vehicle for an operator. The cab described herein provides easier accessibility with lower floor heights, equal stair heights, a narrower seating configuration to accommodate a smaller cab, a shorter tunnel to allow seats to be positioned more inward in the cab while still maintaining appropriate clearances for an operator, and increased visibility with better positioning of the seats and windows of the cab, among others. 
     According to an exemplary embodiment, as shown in  FIGS.  1  and  2   , a vehicle (e.g., a vehicle assembly, a truck, a vehicle base, etc.), shown as vehicle  10 , includes a frame assembly or chassis assembly, shown as chassis  20 . The chassis assembly may support other components of the vehicle  10 . In some embodiments, the chassis  20  extends longitudinally along a length of the vehicle  10 . The chassis  20  may extend substantially parallel to a primary direction of travel of the vehicle  10 . According to an exemplary embodiment, the chassis  20  includes three sections or portions, shown as front section  22 , middle section  24 , and rear section  26 . The middle section  24  of the chassis  20  extends between the front section  22  and the rear section  26 . In some embodiments, the middle section  24  of the chassis  20  couples the front section  22  to the rear section  26 . In other embodiments, the front section  22  is coupled to the rear section  26  by another component (e.g., the body of the vehicle  10 ). 
     As shown in  FIG.  2   , the front section  22  includes a pair of frame portions, frame members, or frame rails, shown as front rail portion  30  and front rail portion  32 . The rear section  26  includes a pair of frame portions, frame members, or frame rails, shown as rear rail portion  34  and rear rail portion  36 . The front rail portion  30  is laterally offset from the front rail portion  32 . Similarly, the rear rail portion  34  is laterally offset from the rear rail portion  36 . This spacing provides frame stiffness and space for vehicle components (e.g., batteries, motors, axles, gears, etc.) between the frame rails. In some embodiments, the front rail portions  30  and  32  and the rear rail portions  34  and  36  extend longitudinally and substantially parallel to one another. The chassis  20  may include additional structural elements (e.g., cross members that extend between and couple the frame rails). 
     In some embodiments, the front section  22  and the rear section  26  are configured as separate, discrete subframes (e.g., a front subframe and a rear subframe). In such embodiments, the front rail portion  30 , the front rail portion  32 , the rear rail portion  34 , and the rear rail portion  36  are separate, discrete frame rails that are spaced apart from one another. In some embodiments, the front section  22  and the rear section  26  are each directly coupled to the middle section  24  such that the middle section  24  couples the front section  22  to the rear section  26 . Accordingly, the middle section  24  may include a structural housing or frame. In other embodiments, the front section  22 , the middle section  24 , and the rear section  26  are coupled to one another by another component, such as a body of the vehicle  10 . 
     In other embodiments, the front section  22 , the middle section  24 , and the rear section  26  are defined by a pair of frame rails that extend continuously along the entire length of the vehicle  10 . In such an embodiment, the front rail portion  30  and the rear rail portion  34  would be front and rear portions of a first frame rail, and the front rail portion  32  and the rear rail portion  36  would be front and rear portions of a second frame rail. In such embodiments, the middle section  24  would include a center portion of each frame rail. 
     In some embodiments, the middle section  24  acts as a storage portion that includes one or more vehicle components. The middle section  24  may include an enclosure that contains one or more vehicle components and/or a frame that supports one or more vehicle components. In some embodiments, the middle section  24  contains or includes one or more electrical energy storage devices (e.g., batteries, capacitors, etc.). In another embodiment, the middle section  24  includes fuel tanks. In yet another embodiment, the middle section  24  defines a void space or storage volume that can be filled by a user. 
     According to an exemplary embodiment, a cabin, operator compartment, or body component, shown as cab  40 , is coupled to a front end portion of the chassis  20  (e.g., the front section  22  of the chassis  20 ). Together, the chassis  20  and the cab  40  define a front end of the vehicle  10 . The cab  40  extends above the chassis  20 . The cab  40  includes an enclosure or main body that defines an interior volume, shown as cab interior  42  that is sized to contain one or more operators. The cab  40  also includes one or more doors  44  that facilitate selective access to the cab interior  42  from outside of the vehicle  10 . The cab interior  42  contains one or more components that facilitate operation of the vehicle  10  by the operator. In one embodiment, the cab interior  42  contains components that facilitate operator comfort (e.g., seats, seatbelts, etc.), user interface components that receive inputs from the operators (e.g., steering wheels, pedals, touch screens, switches, buttons, levers, etc.), and/or user interface components that provide information to the operators (e.g., lights, gauges, speakers, etc.). The user interface components within the cab  40  may facilitate operator control over the drive components of the vehicle  10  and/or over any implements of the vehicle  10 . 
     According to an exemplary embodiment, the vehicle  10  further includes a series of axle assemblies, shown as front axle  50  and rear axles  52 . As shown, the vehicle  10  includes one front axle  50  coupled to the front section  22  of the chassis  20  and two rear axles  52  each coupled to the rear section  26  of the chassis  20 . In other embodiments, the vehicle  10  includes more or fewer axles. In some embodiments, the vehicle  10  includes at least one auxiliary axle that may be raised or lowered to accommodate variations in weight being carried by the vehicle  10 . In one embodiment, the vehicle  10  includes a pusher axle disposed in front of a drive axle. In another embodiment, the vehicle  10  includes a tag axle disposed behind the drive axle. The auxiliary axle may be coupled with the chassis  20  or to an external frame of the vehicle. The vehicle  10  may include any combination of auxiliary axles. The front axle  50  and the rear axles  52  each include a plurality of tractive elements (e.g., wheels, treads, etc.), shown as wheel and tire assemblies  54 . The wheel and tire assemblies  54  are configured to engage a support surface (e.g., roads, the ground, etc.) to support and propel the vehicle  10 . The auxiliary axle may include a plurality of tractive elements. In some embodiments, a wheel and tire assembly  54  of an auxiliary axle is smaller than a wheel and tire assembly  54  of a front axle  50  or a rear axle  52 . The auxiliary axle may be configured such that the wheel and tire assembly  54  engages a support surface only when the auxiliary axle is lowered. The front axle  50  and the rear axles  52  may include steering components (e.g., steering arms, steering actuators, etc.), suspension components (e.g., gas springs, dampeners, air springs, etc.), power transmission or drive components (e.g., differentials, drive shafts, etc.), braking components (e.g., brake actuators, brake pads, brake discs, brake drums, etc.), and/or other components that facilitate propulsion or support of the vehicle. 
       100361  In some embodiments, the vehicle  10  is configured as an electric vehicle that is propelled by an electric powertrain system. As shown in  FIG.  1   , the vehicle  10  includes one or more electrical energy storage devices (e.g., batteries, capacitors, etc.), shown as batteries  60 . As shown, the batteries  60  are positioned within the middle section  24  of the chassis  20 . In other embodiments, the batteries  60  are otherwise positioned throughout the vehicle  10 . The vehicle  10  further includes one or more electromagnetic devices (e.g., motor/generators), shown as drive motors  62 . The drive motors  62  are electrically coupled to the batteries  60 . The drive motors  62  may be configured to receive electrical energy from the batteries  60  and provide rotational mechanical energy to the wheel and tire assemblies  54  to propel the vehicle  10 . The drive motors  62  may be configured to receive rotational mechanical energy from the wheel and tire assemblies  64  and provide electrical energy to the batteries  60 , providing a braking force to slow the vehicle  10 . As shown, the drive motors  62  are positioned within the rear axles  52  (e.g., as part of a combined axle and motor assembly). In other embodiments, the drive motors  62  are otherwise positioned within the vehicle  10 . 
     In other embodiments, the vehicle  10  is configured as a hybrid vehicle that is propelled by a hybrid powertrain system (e.g., a diesel/electric hybrid, gasoline/electric hybrid, natural gas/electric hybrid, etc.). According to an exemplary embodiment, the hybrid powertrain system includes a primary driver (e.g., an engine, a motor, etc.), an energy generation device (e.g., a generator, etc.), and/or an energy storage device (e.g., a battery, capacitors, ultra-capacitors, etc.) electrically coupled to the energy generation device. The primary driver may combust fuel (e.g., gasoline, diesel, etc.) to provide mechanical energy, which a transmission may receive and provide the axle front axle  50  and/or the rear axles  52  to propel the vehicle  10 . Additionally or alternatively, the primary driver may provide mechanical energy to the generator, which converts the mechanical energy into electrical energy. The electrical energy may be stored in the energy storage device (e.g., the batteries  60 ) in order to later be provided to a motive driver. 
     In yet other embodiments, the chassis  20  is further be configured to support non-hybrid powertrains. For example, the powertrain system may include a primary driver that is a compression-ignition internal combustion engine that utilizes diesel fuel. 
     As shown in  FIG.  1   , the vehicle  10  includes a rear assembly, module, implement, body, or cargo area, shown as application kit  80 . The application kit  80  may include one or more implements, vehicle bodies, and/or other components. Although the application kit  80  is shown positioned behind the cab  40 , in other embodiments the application kit  80  extends forward of the cab  40 . The vehicle  10  may be outfitted with a variety of different application kits  80  to configure the vehicle  10  for use in different applications. Accordingly, a common vehicle  10  can be configured for a variety of different uses simply by selecting an appropriate application kit  80 . By way of example, the vehicle  10  may be configured as a refuse vehicle, a concrete mixer, a fire fighting vehicle, an airport fire fighting vehicle, a lift device (e.g., a boom lift, a scissor lift, a telehandler, a vertical lift, etc.), a crane, a tow truck, a military vehicle, a delivery vehicle, a mail vehicle, a boom truck, a plow truck, a farming machine or vehicle, a construction machine or vehicle, a coach bus, a school bus, a semi-truck, a passenger or work vehicle (e.g., a sedan, a SUV, a truck, a van, etc.), and/or still another vehicle.  FIGS.  3 - 8    illustrate various examples of how the vehicle  10  may be configured for specific applications. Although only a certain set of vehicle configurations is shown, it should be understood that the vehicle  10  may be configured for use in other applications that are not shown. 
     According to an exemplary embodiment, the application kit  80  includes various actuators to facilitate certain functions of the vehicle  10 . In one embodiment, the application kit  80  includes hydraulic actuators (e.g., hydraulic cylinders, hydraulic motors, etc.), pneumatic actuators (e.g., pneumatic cylinders, pneumatic motors, etc.), and/or electrical actuators (e.g., electric motors, electric linear actuators, etc.). The application kit  80  may include components that facilitate operation of and/or control of these actuators. In another embodiment, the application kit  80  includes hydraulic or pneumatic components that form a hydraulic or pneumatic circuit (e.g., conduits, valves, pumps, compressors, gauges, reservoirs, accumulators, etc.). By way of another embodiment, the application kit  80  includes electrical components (e.g., batteries, capacitors, voltage regulators, motor controllers, etc.). The actuators may be powered by components of the vehicle  10 . In some embodiments, the actuators are powered by the batteries  60 , the drive motors  62 , or the primary driver (e.g., through a power take off). 
       100411  As shown in  FIG.  3   , the vehicle  10  is configured as a refuse vehicle  100  (e.g., a refuse truck, a garbage truck, a waste collection truck, a sanitation truck, a recycling truck, etc.). Specifically, the refuse vehicle  100  is a front-loading refuse vehicle. In other embodiments, the refuse vehicle  100  is configured as a rear-loading refuse vehicle or a side-loading refuse vehicle. 
     As shown in  FIG.  3   , the application kit  80  of the refuse vehicle  100  includes a rear body or container, shown as refuse compartment  130 , and a pivotable rear portion, shown as tailgate  132 . The refuse compartment  130  may facilitate transporting refuse from various waste receptacles within a municipality to a storage and/or a processing facility (e.g., a landfill, an incineration facility, a recycling facility, etc.). According to an exemplary embodiment, loose refuse is placed into the refuse compartment  130  to be compacted. The refuse compartment  130  may also provide temporary storage for refuse during transport to a waste disposal site and/or a recycling facility. In some embodiments, the refuse compartment  130  includes a hopper volume and storage volume. In this regard, refuse may be initially loaded into the hopper volume and later compacted into the storage volume. According to an exemplary embodiment, the hopper volume is positioned between the storage volume and the cab  40  (e.g., refuse is loaded into a position of the refuse compartment  130  behind the cab  40  and stored in a position further toward the rear of the refuse compartment  130 ). In other embodiments, the storage volume is positioned between the hopper volume and the cab  40  (e.g., in a rear-loading refuse truck, etc.). The tailgate  132  may be pivotally coupled to the refuse compartment  130 , and may be movable between a closed position and an open position by an actuator (e.g., a hydraulic cylinder, an electric linear actuator, etc.), shown as tailgate actuator  134  (e.g., to facilitate emptying the storage volume). 
     As shown in  FIG.  3   , the refuse vehicle  100  also includes an implement, shown as lift assembly  108  (e.g., a front-loading lift assembly, etc.). According to an exemplary embodiment, the lift assembly  108  includes a pair of lift arms  140 , lift arm actuators  142 , and articulation actuators  144 . The lift arms  140  may be rotatably coupled to the chassis  20 . In another embodiment, the lift arms  140  are rotatably coupled to the refuse compartment  130  on each side of the refuse vehicle  100  (e.g., through a pivot, a lug, a shaft, etc.). Such an embodiment provides that the lift assembly  108  extends forward relative to the cab  40  (e.g., a front-loading refuse truck, etc.). In other embodiments, the lift assembly  108  extends rearward relative to the application kit  80  (e.g., a rear-loading refuse truck). In yet other embodiments, the lift assembly  108  extends from a side of the application kit  80  (e.g., a side-loading refuse truck). As shown in  FIG.  3   , the lift arm actuators  142  are positioned such that extension and retraction of the lift arm actuators  142  rotates the lift arms  140  about an axis extending through the pivot. In this regard, the lift arms  140  may be rotated by the lift arm actuators  142  to lift a refuse container over the cab  40 . In an exemplary embodiment, the articulation actuators  144  are positioned to articulate the distal end of the lift arms  140  (e.g., a portion of the lift arms  140  that may be coupled to the refuse container) in order to assist in tipping refuse out of the refuse container and into the refuse compartment  130 . The lift arm actuators  142  may then rotate the lift arms  140  to return the empty refuse container to the ground. 
     According to another exemplary embodiment, as shown in  FIG.  4   , the vehicle  10  is configured as a mixer truck (e.g., a concrete mixer truck, a mixer vehicle, etc.), shown as mixer truck  200 . Specifically, the mixer truck  200  is a rear-discharge concrete mixer truck. In other embodiments, the mixer truck  200  is a front-discharge concrete mixer truck. 
     As shown in  FIG.  4   , the application kit  80  includes a mixing drum assembly (e.g., a concrete mixing drum), shown as drum assembly  230 . The drum assembly  230  includes a mixing drum  232 , a drum drive system  234  (e.g., a rotational actuator or motor), an inlet, shown as hopper  236 , and an outlet, shown as chute  238 . The mixing drum  232  may be coupled to the chassis  20  and may be disposed behind the cab  40  (e.g., at the rear and/or middle of the chassis  20 ). In an exemplary embodiment, the drum drive system  234  is coupled to the chassis  20  and configured to selectively rotate the mixing drum  232  about a central, longitudinal axis. According to an exemplary embodiment, the central, longitudinal axis of the mixing drum  232  is elevated from the chassis  20  (e.g., from a horizontal plan extending along the chassis  20 ) at an angle in the range of five degrees to twenty degrees. In other embodiments, the central, longitudinal axis is elevated by less than five degrees (e.g., four degrees, etc.). In yet another embodiment, the mixer truck  200  includes an actuator positioned to facilitate adjusting the central, longitudinal axis to a desired or target angle (e.g., manually in response to an operator input/command, automatically according to a control system, etc.). 
     The mixing drum  232  may be configured to receive a mixture, such as a concrete mixture (e.g., cementitious material, aggregate, sand, etc.), through the hopper  236 . In some embodiments, the mixer truck  200  includes an injection system (e.g., a series of nozzles, hoses, and/or valves). The injection system may include an injection valve that selectively fluidly couples a supply of fluid to the inner volume of the mixing drum  232 . In one embodiment, the injection system is used to inject water and/or chemicals (e.g., air entrainers, water reducers, set retarders, set accelerators, superplasticizers, corrosion inhibitors, coloring, calcium chloride, minerals, and/or other concrete additives, etc.) into the mixing drum  232 . The injection valve may facilitate injecting water and/or chemicals from a fluid reservoir (e.g., a water tank, etc.) into the mixing drum  232 , while preventing the mixture in the mixing drum  232  from exiting the mixing drum  232  through the injection system. In some embodiments, one or more mixing elements (e.g., fins, etc.) are positioned in the interior of the mixing drum  232 , and may be configured to agitate the contents of the mixture when the mixing drum  232  is rotated in a first direction (e.g., counterclockwise, clockwise, etc.), and drive the mixture out through the chute  238  when the mixing drum  232  is rotated in a second direction (e.g., clockwise, counterclockwise, etc.). In some embodiments, the chute  238  includes an actuator positioned such that the chute  238  may be selectively pivotable to position the chute  238  (e.g., vertically, laterally, etc.), for example, at an angle at which the mixture is expelled from the mixing drum  232 . 
     As shown in  FIG.  5   , the vehicle  10  is configured as a fire fighting vehicle or fire apparatus (e.g., a turntable ladder truck, a pumper truck, a quint, etc.), shown as fire fighting vehicle  300 . As shown in  FIG.  5   , the fire fighting vehicle  300  is configured as a rear-mount aerial ladder truck. In other embodiments, the fire fighting vehicle  300  is configured as a mid-mount aerial ladder truck, a quint fire truck (e.g., including an on-board water storage, a hose storage, a water pump, etc.), a tiller fire truck, a pumper truck (e.g., without an aerial ladder), or another type of response vehicle. According to an exemplary embodiment, the vehicle  10  is be configured as a police vehicle, an ambulance, a tow truck, or still other vehicles used for responding to a scene (e.g., an accident, a fire, an incident, etc.). 
     As shown in  FIG.  5   , in the fire fighting vehicle  300 , the application kit  80  is positioned mainly rearward from the cab  40 . The application kit  80  includes deployable stabilizers (e.g., outriggers, downriggers, etc.), shown as outriggers  330 , that are coupled to the chassis  20 . The outriggers  330  may be configured to selectively extend from each lateral side and/or the rear of the fire fighting vehicle  300  and engage a support surface (e.g., the ground) in order to provide increased stability while the fire fighting vehicle  300  is stationary. This increased stability is desirable when the ladder assembly  308  is in use (e.g., extended from the fire fighting vehicle  300 ) to prevent tipping. In some embodiments, the application kit  80  further includes various storage compartments (e.g., cabinets, lockers, etc.) that are selectively opened and/or accessed for storage and/or component inspection, maintenance, and/or replacement. 
     As shown in  FIG.  5   , the application kit  80  includes a ladder assembly  308  coupled to the chassis  20 . The ladder assembly  308  includes a series of ladder sections  340  that are slidably coupled with one another such that the ladder sections  340  may extend and/or retract (e.g., telescope) relative to one another to selectively vary a length of the ladder assembly  308 . A base platform, shown as turntable  342 , is rotatably coupled to the chassis  20  and to a proximal end of a base ladder section  340  (i.e., the most proximal of the ladder sections  340 ). The turntable  342  may be configured to rotate about a vertical axis relative to the chassis  20  to rotate the ladder sections  340  about the vertical axis (e.g., up to 360 degrees, etc.). The ladder sections  340  may rotate relative to the turntable  342  about a substantially horizontal axis to selectively raise and lower the ladder sections  340  relative to the chassis  20 . As shown, a water turret or implement, shown as monitor  344 , is coupled to a distal end of a fly ladder section  340  (i.e., the most distal of the ladder sections  340 ). The monitor  344  may be configured to expel water and/or a fire suppressing agent (e.g., foam, etc.) from a water storage tank and/or an agent tank onboard the fire fighting vehicle  300 , and/or from an external source (e.g., a fire hydrant, a separate water/pumper truck, etc.). In some embodiments, the ladder assembly  308  further includes an aerial platform coupled to the distal end of the fly ladder section  340  and configured to support one or more operators. 
     According to another exemplary embodiment, as shown in  FIG.  6   , the vehicle  10  is configured as a fire fighting vehicle, shown as airport rescue and fire fighting (ARFF) truck  400 . As shown in  FIG.  6   , the application kit  80  is positioned primarily rearward of the cab  40 . As shown, the application kit  80  includes a series of storage compartments or cabinets, shown as compartments  430 , that are coupled to the chassis  20 . The compartments  430  may store various equipment or components of the ARFF truck  400 . 
     The application kit  80 , as shown in  FIG.  6   , includes a pump system  432  (e.g., an ultra-high-pressure pump system, etc.) positioned within one of the compartments  430  near the center of the ARFF truck  400 . The application kit  80  further includes a water tank  434 , an agent tank  436 , and an implement or water turret, shown as monitor  438 . The pump system  432  may include a high pressure pump and/or a low pressure pump, which may be fluidly coupled to the water tank  434  and/or the agent tank  436 . The pump system  432  may to pump water and/or fire suppressing agent from the water tank  434  and the agent tank  436 , respectively, to the monitor  438 . The monitor  438  may be selectively reoriented by an operator to adjust a direction of a stream of water and/or agent. As shown in  FIG.  6   , the monitor  438  is coupled to a front end of the cab  40 . 
     As shown in  FIG.  7   , the vehicle  10  is configured as a lift device, shown as boom lift  500 . The boom lift  500  may be configured to support and elevate one or more operators. In other embodiments, the vehicle  10  is configured as another type of lift device that is configured to lift operators and/or material, such as a skid-loader, a telehandler, a scissor lift, a fork lift, a vertical lift, and/or any other type of lift device or machine. 
     As shown in  FIG.  7   , the application kit  80  includes a base assembly, shown as turntable  504  that is rotatably coupled to the chassis  20 . The turntable  504  may be configured to selectively rotate relative to the chassis  20  about a substantially vertical axis. In some embodiments, the turntable  504  includes a counterweight positioned near the rear of the turntable  504 . The turntable  504  is rotatably coupled to a lift assembly, shown as boom assembly  508 . The boom assembly  508  includes a first section or telescoping boom section, shown as lower boom  540 . The lower boom  540  includes a series of nested boom sections that extend and retract (e.g., telescope) relative to one another to vary a length of the boom assembly  508 . The boom assembly  508  further includes a second boom section or four bar linkage, shown as upper boom  542 . The upper boom  542  may include structural members that rotate relative to one another to raise and lower a distal end of the boom assembly  508 . In other embodiments, the boom assembly  508  includes more or fewer boom sections (e.g., one, three, five, etc.) and/or a different arrangement of boom sections. 
     As shown in  FIG.  7   , the boom assembly  508  includes a first actuator, shown as lower lift cylinder  544 . The lower boom  540  is pivotally coupled (e.g., pinned, etc.) to the turntable  504  at a joint or lower boom pivot point. The lower lift cylinder  544  (e.g., a pneumatic cylinder, an electric actuator, a hydraulic cylinder, etc.) is coupled to the turntable  504  at a first end and coupled to the lower boom  540  at a second end. The lower lift cylinder  544  may be configured to raise and lower the lower boom  540  relative to the turntable  504  about the lower boom pivot point. 
     The boom assembly  508  further includes a second actuator, shown as upper lift cylinder  546 . The upper boom  542  is pivotally coupled (e.g., pinned) to the upper end of the lower boom  540  at a joint or upper boom pivot point. The upper lift cylinder  546  (e.g., a pneumatic cylinder, an electric actuator, a hydraulic cylinder, etc.) is coupled to the upper boom  542 . The upper lift cylinder  546  may be configured to extend and retract to actuate (e.g., lift, rotate, elevate, etc.) the upper boom  542 , thereby raising and lowering a distal end of the upper boom  542 . 
     As shown in  FIG.  7   , the application kit  80  further includes an operator platform, shown as platform assembly  550 , coupled to the distal end of the upper boom  542  by an extension arm, shown as jib arm  552 . The jib arm  552  may be configured to pivot the platform assembly  550  about a lateral axis (e.g., to move the platform assembly  550  up and down, etc.) and/or about a vertical axis (e.g., to move the platform assembly  550  left and right, etc.). 
     According to an exemplary embodiment, the platform assembly  550  provides a platform configured to support one or more operators or users. In some embodiments, the platform assembly  550  includes accessories or tools configured for use by the operators. In one embodiment, the platform assembly  550  includes pneumatic tools (e.g., an impact wrench, airbrush, nail gun, ratchet, etc.), plasma cutters, welders, spotlights, etc. In other embodiments, the platform assembly  550  includes a control panel (e.g., a user interface, a removable or detachable control panel, etc.) configured to control operation of the boom lift  500  (e.g., the turntable  504 , the boom assembly  508 , etc.) from the platform assembly  550  or remotely. In other embodiments, the platform assembly  550  is omitted, and the boom lift  500  includes an accessory and/or tool (e.g., forklift forks, etc.) coupled to the distal end of the boom assembly  508 . 
     According to an exemplary embodiment, as shown in  FIG.  8   , the vehicle  10  is configured as a lift device, shown as scissor lift  600 . As shown in  FIG.  8   , the application kit  80  includes a body, shown as lift base  604 , coupled to the chassis  20 . The lift base  604  is coupled to a scissor assembly, shown as lift assembly  608 , such that the lift base  604  supports the lift assembly  608 . The lift assembly  608  is configured to extend and retract, raising and lowering between a raised position and a lowered position relative to the lift base  604 . 
     As shown in  FIG.  8   , the lift base  604  includes a series of actuators, stabilizers, downriggers, or outriggers, shown as leveling actuators  630 . The leveling actuators  630  may extend and retract vertically between a stored position and a deployed position. In the stored position, the leveling actuators  630  may be raised, such that the leveling actuators  630  do not contact the ground. Conversely, in the deployed position, the leveling actuators  630  may engage the ground to lift the base assembly  604 . The length of each of the leveling actuators  630  in their respective deployed positions may be varied in order to adjust the pitch (e.g., rotational position about a lateral axis) and the roll (e.g., rotational position about a longitudinal axis) of the base assembly  604  and/or the chassis  20 . Accordingly, the lengths of the leveling actuators  630  in their respective deployed positions may be adjusted to level the base assembly  604  with respect to the direction of gravity (e.g., on uneven, sloped, pitted, etc. terrain). The leveling actuators  630  may lift the wheel and tire assemblies  54  off of the ground to prevent movement of the scissor lift  600  during operation. In other embodiments, the leveling actuators  630  are omitted. 
     According to an exemplary embodiment, the lift assembly  608  includes a series of subassemblies, shown as scissor layers  640 , each including a pair of inner members  642  and a pair of outer members  644 . The scissor layers  640  may be stacked atop one another in order to form the lift assembly  608 . The inner members  642  may be pivotally coupled to the outer members  644  near the center of both the inner members  642  and the outer members  644 . In this regard, the inner members  642  may pivot relative to the outer members  644  about a lateral axis. Each of the inner members  642  and the outer members  644  may include a top end and a bottom end. The bottom end of each inner member  642  may be pivotally coupled to the top end of the outer member  644  immediately below it, and the bottom end of each outer member  644  may be pivotally coupled to the top end of the inner member immediately below it. Accordingly, each of the scissor layers  640  may be coupled to one another such that movement of one scissor layer  640  causes a similar movement in all of the other scissor layers  640 . The bottom ends of the inner member  642  and the outer member  644  that make up the lowermost scissor layer  640  may be coupled to the base assembly  604 . The top beds of the inner member  642  and the outer member  644  that make up the uppermost scissor layer  640  may be coupled to the platform assembly  650 . In some embodiments, scissor layers  640  may be added to, or removed from, the lift assembly  608  in order to increase, or decrease, the fully extended height of the lift assembly  608 . 
     As shown in  FIG.  8   , the lift assembly  608  also includes one or more lift actuators  646  (e.g., hydraulic cylinders, pneumatic cylinders, motor-driven leadscrews, etc.) configured to extend and retract the lift assembly  608 . The lift actuators  646  may be pivotally coupled to an inner member  642  at a first end and pivotally coupled to an inner member  642  of another scissor layer  640  at a second end. In an exemplary embodiment, these inner members  642  belong to a first scissor layer  640  and a second scissor layer  640  (which may be separated by a third scissor layer  640 ). In other embodiments, the lift actuators  646  are arranged in other configurations (e.g., the first scissor layer  640  and the second scissor layer  640  are not separated by a third scissor layer  640 , etc.). 
     According to an exemplary embodiment, as distal or upper end of the lift assembly  608  is coupled to an operator platform, shown as platform assembly  650 . The lift actuators  646  may be configured to actuate the lift assembly  608  to selectively reposition the platform assembly  650  between a lowered position (e.g., where the platform assembly  650  is proximate to the lift base  604 ) and a raised position (e.g., where the platform assembly  650  is at an elevated height relative to the lift base  604 ). Specifically, in some embodiments, extension of the lift actuators  646  moves the platform assembly  650  upward (e.g., extending the lift assembly  608 ), and retraction of the lift actuators  646  moves the platform assembly  650  downward (e.g., retracting the lift assembly  608 ). In other embodiments, extension of the lift actuators  646  retracts the lift assembly  608 , and retraction of the lift actuators  646  extends the lift assembly  608 . In some embodiments, the outer members  644  are parallel to and/or in contact with one another when the lift assembly  608  is in the stored position. 
     In some embodiments, the platform assembly  650  includes a platform that is configured to support one or more operators or users. Similar to the platform assembly  550 , the platform assembly  650  may include accessories or tools (e.g., pneumatic tools, plasma cutters, welders, spotlights, etc.) configured for use by an operator. The platform assembly  650  may include a control panel to control operation of the scissor lift  600 . 
     According to an exemplary embodiment, as shown in  FIG.  9 A , the chassis  20  of a vehicle  10  includes a first frame rail, shown as frame rail  902 , and a second frame rail, shown as frame rail  904 . The first frame rail  902  and the second frame rail  904  may extend continuously along the entire length of the vehicle  10 . In other embodiments, the first and second frame rails  902 ,  904  extend only a portion of the length of the vehicle  10 . In one embodiment, the first frame rail  902  is parallel to the second frame rail  904 . In another embodiment, at least one portion of the first frame rail  902  is parallel to at least one portion of the second frame rail  904 . In another embodiment, the first frame rail  902  and the second frame rail  904  have a uniform cross-section along the entire length of the frame rails  902 ,  904 . In such an embodiment, each frame rail  902 ,  904  defines a constant size and shape along the entire frame rail  902 ,  904 . In another embodiment, the first frame rail  902  and the second frame rail  904  do not have a uniform cross-section along the entire length of the frame rails  902 ,  904 . In some embodiments, the first frame rail  902  mirrors the second frame rail  904  (e.g., the first frame rail  902  and the second frame rail  904  define reflective symmetry about a center axis extending longitudinally along a centerline of the chassis  20 ). In other embodiments, the first frame rail  902  is different from the second frame rail  904 . 
     According to an exemplary embodiment, as shown in  FIG.  9 A , the chassis  20  includes three sections. The chassis  20  may include a first section, shown as front portion  906 , a second section, shown as transition portion  908 , and a third section, shown as rear portion  910 . The front portion  906  may correspond to a front portion of the first frame rail  902  and a front portion of the second frame rail  904 . The transition portion  908  may correspond to a transition portion of the first frame rail  902  and a transition portion of the second frame rail  904 . The rear portion  910  may correspond to a rear portion of the first frame rail  902  and a rear portion of the second frame rail  904 . The front portion  906  may define a width, shown as first width  912 . The first width  912  may be defined by a distance laterally between an exterior of the front portion of the first frame rail  902  and an exterior of the front portion of the second frame rail  904 . The rear portion  910  may define a width, shown as second width  914 . The second width  914  may be defined by a distance laterally between an exterior of the rear portion of the first frame rail  902  and an exterior of the rear portion of the second frame rail  904 . In one embodiment, the first width  912  is smaller than the second width  914 . In such an embodiment, the chassis  20  comprises an inward-offset rail configuration. In another embodiment, the first width  912  is larger than the second width  914 . In such an embodiment, the chassis  20  comprises an outward-offset rail configuration. In another embodiment, the first width  912  and the second width  914  are the same. In other embodiments, the chassis  20  has more or less sections. 
     In one embodiment, the front portion  906  is disposed at the same elevation (e.g., a height off a ground on which the vehicle  10  travels) as the rear portion  910 . In another exemplary embodiment, the front portion  906  is disposed at a different elevation than the rear portion  910 . In one embodiment, the front portion  906  is disposed lower than the rear portion  910 . In another embodiment, the front portion  906  is disposed higher than the rear portion  910 . 
     In one embodiment, the front portions of the frame rails  902 ,  904  are the same size as the rear portions of the frame rails  902 ,  904 . The front portions of the frame rails  902 ,  904  may have the same length as the rear portions of the frame rails  902 ,  904 . The front portions of the frame rails  902 ,  904  may have the same width as the rear portions of the frame rails  902 ,  904 . In another embodiment, the front portions of the frame rails  902 ,  904  are a different size than the rear portions of the frame rails  902 ,  904 . The front portions of the frame rails  902 ,  904  may have a different length than the rear portions of the frame rails  902 ,  904 . In one embodiment, the front portions of the frame rails  902 ,  904  is longer than the rear portions of the frame rails  902 ,  904 . In another embodiment, the front portions of the frame rails  902 ,  904  is shorter than the rear portions of the frame rails  902 ,  904 . 
     According to an exemplary embodiment, the transition portion  908  couples the front portion  906  with the rear portion  910 . As shown in  FIG.  9 A , the transition portion  908  extends from a rear side of the front portion  906  to a front side of the rear portion  910 . According to an exemplary embodiment, the transition portion  908  is oriented at an angle compared to the front portion  906  and the rear portion  910  (e.g., not parallel to the first portion  906  or the rear portion  910 ). The transition portion  908  may be any size, shape, or orientation configured to couple the front portion  906  with the rear portion  910 . In an exemplary embodiment, the transition portion  908  is oriented at a gradual angle to couple the front portion  906  with the rear portion  910 . A gradual angle may be any angle between zero and ninety degrees. A length of the transition portion  908 , shown as length  916 , may be based, in part, on the angle of orientation. In another embodiment, the transition portion  908  is oriented at a sharper angle. According to an exemplary embodiment, the transition portion  908  is oriented at a ninety-degree angle. The transition portion  908  oriented at a sharper angle may have a shorter length  916  than a transition portion  908  oriented at a more gradual angle. The size, shape, or orientation of the transition portion  908  of the first frame rail  902  may be the same as the size, shape, or orientation of the transition portion  908  of the second frame rail  904 . Being the same may mean the transition portion  908  of the first frame rail  902  is mirroring the transition portion  908  of the second frame rail  904 . In another embodiment, the size, shape, or orientation of the transition portion  908  of the first frame rail  902  is different from the size, shape, or orientation of the second frame rail  904 . 
     According to an exemplary embodiment, the transition portion  908  supports a front axle  50  of the vehicle  10  and the rear portion  910  supports a rear axle  52 . In another embodiment, the front portion  906  supports the front axle  50  and the rear portion supports the rear axle  52 . In another embodiment, the rear portion  910  supports the front axle  50  and the rear axle  52 . Any portion of the chassis  20  may support any combination of front and rear axles  50 ,  52 . 
     In another embodiment, the chassis  20  supports an auxiliary axle, shown as auxiliary axle  911 . The auxiliary axle  911  may be a pusher axle disposed in front of a front-most drive axle (e.g., a front-most one of the rear axles  52 ). In other embodiments, the auxiliary axle  911  is a tag axle disposed behind a rear-most drive axle (e.g., a rear-most one of the rear axles  52 ). The auxiliary axle  911  may be coupled with the chassis  20 . The auxiliary axle  911  may be coupled with any portion of the chassis  20 . In other embodiments, the auxiliary axle  911  is coupled to an external frame of the vehicle  10 . In one embodiment, the external frame is coupled with the chassis  20  such that the auxiliary axle  911  is disposed at a location offset from the chassis  20  (e.g., behind a back end of the chassis  20 ). In some embodiments, the auxiliary axle  911  may be configured to move between a first position (e.g., a passive position) and a second position (e.g., an active position). When in the first position, the auxiliary axle  911  may be disposed at an elevation such that a wheel and tire assembly  54  coupled with the auxiliary axle  911  does not contact a support surface (e.g., the ground). In the first position, the auxiliary axle  911  may provide no support for the weight of the vehicle  10 . When in the second position, the auxiliary axle  911  may be disposed at an elevation such that the wheel and tire assembly  54  coupled with the auxiliary axle  911  does contact a support surface (e.g., the ground). In the second position, the auxiliary axle  911  does provide support for the weight of the vehicle  10 . 
     In some embodiments, the chassis  20  does not have a transition portion  908 . The chassis  20  may include only one portion that extends the whole length of the vehicle  10 . In other embodiments, the chassis  20  may include a front portion  906  that extends from a front side of the rear portion  910 . In another embodiment, the front portion  906  and the rear portion  910  can overlap. 
     According to another exemplary embodiment, as shown in  FIG.  9 B , the chassis  20  can include a first frame rail  902 , a second frame rail  904 , and an extension structure, shown as frame extension  918 . The frame extension  918  may comprise a single section or the frame extension  918  may comprise a plurality of sections. In one embodiment, the first frame rail  902  and the second frame rail  904  comprise a rear portion  910  of the chassis  20  and the frame extension  918  comprises a front portion  906  of the chassis  20 . In another embodiment, the frame extension  918  comprises the front portion  906  and a transition portion  908  of the chassis  20 . In some embodiments, the frame extension  918  is configured to bolt to the frame rails  902 ,  904  of the chassis  20 . As shown in  FIG.  9 B , the frame extension  918  is configured to fit between the frame rails  902 ,  904  such that the frame extension  918  can be bolted to an inner surface of each frame rail  902 ,  904 . The frame extension  918  may also be bolted to other portions of the frame rails  902 ,  904  (e.g., flanges, top, bottom, etc.). In another embodiment, the frame rails  902 ,  904  fit inside the frame extension  918 . In such an embodiment, the frame extension  918  is configured to be bolted to an outer surface of each frame rail  902 ,  904 . 
     According to an exemplary embodiment, as shown in  FIG.  9 B , the frame extension  918  defines the transition portion  908  and the front portion  906 . The transition portion  908  may be at least partially disposed between the first frame rail  902  and the second frame rail  904 . The frame extension  918  may be coupled with the frame rails  902 ,  904 . In some embodiments, the frame extension  918  is bolted to the inside of the frame rails  902 ,  904 . In one embodiment, the transition portion  908  extends forward from the frame rails  902 ,  904 . In another embodiment, the frame extension  918  is a single portion (e.g., does not include both a front portion  906  and a transition portion  908 ) such that the frame extension  918  is capable of supporting the cab  40 . As shown in  FIG.  9 B , the frame extension  918  starts with a height similar to the height of the frame rails  902 ,  904 . In one embodiment, that height of the frame extension  918  can extend until the front portion  906 . In another embodiment, the frame extension  918  can taper downwardly as it extends toward the front portion  906  such that a front of the frame extension  918  is at a lower height than a back of the frame extension  918 . In other embodiments, the front of the frame extension  918  defines a height that is greater than the back of the frame extension  918 . In another embodiment, at least part of the frame extension  918  has a width similar to the width  914  of the rear portion  910  of the chassis  20  (e.g., the frame extension  918  can couple with both frame rails  902 ,  904 ). In another embodiment, the frame extension  918  defines more than one width. In one embodiment, the transition portion  908  of the frame extension  918  has a first width and the front portion  906  has a second width. In another embodiment, the transition portion  908  includes a first width and a second width, and the front portion  906  includes a third width. In such an example, the transition portion  908  starts with a width similar to the width  914  of the rear portion  910  of the chassis  20  and becomes a different width as the frame extension  918  extends away from the rear portion  910  of the chassis  20 . The width of the frame extension  918  may increase or decrease as it extends away from the rear portion  910 . In one embodiment, the front portion  906  of the frame extension  918  extends in a direction perpendicular to the frame rails  902 ,  904 . In some embodiments, the front portion  906  has a width that is at least twice as wide as the part of the transition portion  908  that couples with the front portion  906 . 
     According to an exemplary embodiment, as shown in  FIGS.  10 - 12   , a cab  40  of a vehicle  10  includes a tunnel, shown as tunnel  1002 . The tunnel  1002  protrudes into a cab interior  42  and extends longitudinally along the cab  40  (e.g., in a direction substantially parallel to the frame rails  902 ,  904 ). The tunnel  1002  may be a recess defined by the body of the cab  40  that is configured to receive at least part of the chassis  20 . In some embodiments, the cab  40  is supported by at least the front portion  906  of the chassis  20 . In some embodiments, the front portion  906  of the chassis  20  is disposed within the tunnel  1002  and supports the chassis  20  via the tunnel  1002 . In other embodiments, the front portion  906  of the chassis  20  is wider than the tunnel  1002  such that front portion  906  does not fit in the tunnel  1002 . In such an embodiment, the bottom of the cab  40  rests on top of the front portion  906  of the chassis  20 . In such an embodiment, a transition portion  908  of the chassis  20  may be configured to be disposed, at least partially, within the tunnel  1002  and couple with a front portion  906  that is disposed below the tunnel  1002 . The tunnel  1002  may extend a full length of the cab  40  or may extend only part of the length of the cab  40 . The tunnel  1002  may divide the cab interior  42  into sides, shown as first side  1004  and second side  1006 . Both the first side  1004  and the second side  1006  may be configured to provide an operator of the vehicle  10  with room, comfort, and accessibility to operate the vehicle  10 . The sides  1004 ,  1006  may be configured the same or they may be configured differently. 
     According to an exemplary embodiment, a width  1008  of the tunnel  1002  is based, at least in part, on the width  912  of the front portion  906  of the chassis  20 . For example, the lateral width  1008  of the tunnel  1002  is greater than the width  912  defined laterally between exteriors of the first frame rail  902  and the second frame  904  rail at the front portion  906  of the chassis  20 . This arrangement enables the front portion  906  of the chassis  20  to be at least partially received within the tunnel  1002 , which efficiently supports the cab  40  on the chassis  20  and enables the cab  40  to define a smaller lateral width when compared due to conventional cab designs. The tunnel  1002  may have a width  1008  large enough to fit the front portion of the first frame rail  902  and the front portion of the second frame rail  904  within the tunnel  1002 . The smaller the width  912 , the smaller the width  1008  of the tunnel  1002  may be. In another embodiment, the width  1008  is smaller than the width  914  of the rear portion  910  of the chassis  20 . In such an embodiment, the width  912  of the front portion  906  is smaller than the width  914  of the rear portion  910 . The width  1008  of the tunnel  1002  may be configured to accommodate the front portion  906  and not the rear portion  910 . 
     In another embodiment, a width  1008  of the tunnel is based, at least in part, on the width of a transition portion  908  of a frame extension  918 . The frame extension  918  may extend within the tunnel  1002  such that the front portion  906  is disposed either within the tunnel  1002  or below the cab  40  so as to support at least a front portion of the cab  40 . 
     As shown in  FIGS.  10 - 12   , each side  1004 ,  1006  of the cab  40  includes a seat  1010  for an operator, according to an exemplary embodiment. In other embodiments, only one side of the can includes a seat. The seat  1010  includes a back portion, shown as back rest  1020 , and a bottom portion or cushion, shown as seat support  1022 . In one embodiment, a location of the seat  1010  is based, at least in part, on the width  1008  of the tunnel  1002 . The smaller the width  1008  of the tunnel  1002 , the closer to the center of the cab  40  the seat  1010  may be. In other words, the smaller the width  1008  of the tunnel  1002 , the closer a first seat  1010  may be laterally to a second seat  1010 . According to an exemplary embodiment, a distance  1012  between a centerline of a first seat  1010  and a centerline of a second seat  1010  is less than or equal to about 45 inches. In one embodiment, the cab  40  includes a display  1018  fixed to a front console (e.g., dashboard) of the cab  40 . The first seat  1010  and the second seat  1010  can be disposed such that an operator in both seats  1010  can access the display. The display  1018  may include input devices (e.g., buttons, switches, levers, pedals, etc.) or output devices (e.g., lights, gauges, speakers, etc.), or any combination thereof, that aid in the operation of the vehicle  10 . The display  1018  may be configured to be accessible by an operator on either side  1004 ,  1006  of the cab  40  without having to move at all (e.g., all components are stationary), or with only moving slightly (e.g., swivel, tilt, etc.). In other embodiments, the cab  40  includes separate displays  1018  for each side  1004 ,  1006  of the cab  40 . 
     According to an exemplary embodiment, the location of the seat  1010  provides adequate clearance, shown as clearance  1024 , for an operator. In one embodiment, the location of the seat provides a shoulder clearance measured from a centerline of the seat  1010  to an inner surface of a door  1404  of the cab  40 , or a component thereof (e.g., a window, a handle, an armrest), of greater than or equal to about 18 inches or greater than or equal to about 18.5 inches. In another embodiment, the location of the seat  1010  provides an elbow clearance measured from the centerline of the seat  1010  to an inner surface of a door  1404  of the cab  40  of greater than or equal to about 15 inches or greater than or equal to about 15.5 inches. In one embodiment, a window on a door of the cab  40  is positioned rearward to provide additional shoulder or elbow clearance. 
     The body of the cab  40  defines a front width  1014  and a rear width  1016 . In general, the lateral widths  1014 ,  1016  defined by the cab  40  are smaller than convention cab designs, which enables the cab  40  to provide better visibility for an operator within the cab interior  42 . In some embodiments, the widths  1014 ,  1016  may be measured from an exterior of a first side of the cab  40  to an exterior of a second side of the cab  40 . In some embodiments, the front width  1014  is smaller than the back width  1016 . In some embodiments, the front width  1014  is a maximum of about 80 inches. For example, the front width  1014  may be less than or equal to about 80 inches. In some embodiments, the rear width  1016  is maximum of about 86 inches. For example, the rear width may be less than or equal to about 86 inches. 
     According to an exemplary embodiment, as shown in  FIG.  12   , a height  1102  of the tunnel  1002  is based, at least in part, on a height  1108  of a top of the front portion  906  of the chassis  20 . For example, the height  1102  of the tunnel  1002  may be defined between a bottom surface  1104  of the cab  40  and an uppermost surface or top  1106  of the tunnel  1002 . In some embodiments, the height  1108  of the front portion  906  of the chassis  20  may be different than the height of the rear portion  910  of the chassis  20 . According to an exemplary embodiment, a portion of the tunnel  1002  rests on top of the front portion  906  of the chassis  20 . The portion of the tunnel  1002  may directly contact the chassis  20 . Direct contact may include the tunnel  1002  directly contacting the chassis  20  without any other material separating the tunnel  1002  from the chassis  20 . Direct contact may also include other material or small devices that are disposed between the tunnel  1002  and the chassis (e.g., padding, fasteners, supportive devices, etc.). In other embodiments, the chassis  20  contacts the tunnel  1002  indirectly. Indirect contact may include having a larger obstruction or piece of equipment disposed between the chassis  20  and the tunnel  1002  (e.g., an engine disposed in the tunnel  1002 , etc.). 
     In some embodiments, a clearance distance  1110  is defined between the bottom surface  1104  of the cab  40  and a ground  1112 . The clearance distance  1110  may have a minimum distance specified by industry standard. According to an embodiment, the industry standard for the clearance distance  1110  is 13 inches above the ground  1112  and the height  1108  of the top of the front portion  906  of the chassis  20  is about 35 inches. In such an embodiment, the height  1102  of the tunnel  1002  is about 22 inches. 
     In another embodiment, the height  1102  of the tunnel  1002  is based, at least on part, on a height of a top of the frame extension  918 . The frame extension  918  may be disposed within the tunnel  1002  such that the height  1102  of the tunnel  1002  accommodates the height of the frame extension  918 . The height of the frame extension  918  may vary so the height  1102  of the tunnel  1002  may vary accordingly. 
     According to an exemplary embodiment, the top  1106  of the tunnel  1002  is lower than a top of the seat support  1022  (e.g., closer to the ground  1112 ). In some embodiments, the top  1106  of the tunnel  1002  is lower than the entire seat support  1022 . In such an embodiment, the seat  1010  may be positioned such that part of the seat support  1022  is disposed over the tunnel  1002 . Similarly, an arm or shoulder of an operator sitting in the seat  1010  may be disposed above the tunnel  1002  since there is no obstruction preventing such arrangement. In general, arranging the uppermost surface or top  1106  of the tunnel  1002  below the seat supports  1022  enables the cab  40  to define a reduced lateral width (e.g., the front width  1014  and the rear width  1016 ), when compared to convention cab designs, because the seats  1010  are positioned laterally closer to one another (e.g., the distance  1012  is reduced when compared to convention cab designs). 
     According to an exemplary embodiment, as shown in  FIG.  13   , a rear of the cab  40  is supported by an external support structure, shown as support arm  1201 . Supporting the rear of the cab  40  with the support arm  1201  allows the cab  40  to extend over other elements of the vehicle  10  (e.g., a wheel and tire assembly  54 ) The support arm  1201  may be a part of the cab  40  or may be coupled to the cab  40 . The support arm  1201  may extend from the cab  40  at any location such that an end of the support arm  1201  contacts a support point, shown as pad  1202 . Pad  1202  may include cushioning devices (e.g., suspension devices) configured to reduce the impact of any forces felt by the vehicle  10 . Pad  1202  may include receiving devices (e.g., notches, holes, rails, etc.) configured to keep the support arm  1201  in a desired location. In some embodiments, the pad  1202  is coupled to the chassis  20 . In some embodiments, the pad  1202  is coupled with a side of the chassis  20 . In other embodiments, the pad  1202  is coupled with a top of the chassis  20 . The pad  1202  is configured to receive the end of the support arm  1201  and keep the cab  40  at a desired orientation. In some embodiments, a first support arm  1201  extends from the cab  40  and contacts a first pad  1202  coupled with a first frame rail  902  of the chassis  20  and a second support arm  1201  extends from the cab  40  and contacts a second pad  1202  coupled with a second frame rail  904 . In another embodiment, a support arm  1201  extends from the cab  40  and splits into two support arms  1201 , each configured to contact a different frame rail  902 ,  904 . In another embodiment, a support arm  1201  extends from the cab  40  and contacts a pad  1202  disposed between the two frame rails  902 ,  904 . The pad  1202  may extend between the first frame rail  902  and the second frame rail  904  such that the support arm  1201  contacts the pad  1202  at a location between the first frame rail  902  and the second frame rail  904 . The support arm  1201  may also be configured to contact a portion of the frame extension instead of, or along with, the frame rails  902 .  904 . 
     According to an exemplary embodiment, the cab  40  is supported by the chassis  20  via the tunnel  1002 . In one embodiment, an entire length of the tunnel  1002  rests upon the front portion  906  of the chassis  20 . In another embodiment, a portion of the tunnel  1002  rests upon a front portion  906  of the chassis  20 . The portion of the tunnel  1002  may be a front portion. A rear portion of the tunnel  1002  may be supported by the support arm  1201 . In another embodiment, the cab  40  is supported by the frame extension  918  of the chassis  20 . The frame extension  918  may support the cab  40  via the tunnel  1002 . In one embodiment, the front portion  906  of the frame extension  918  is disposed within the tunnel  1002  such that at least the front of the tunnel  1002  is supported by the frame extension  918 . In another embodiment, the front portion  906  of the frame extension  918  is wider than the tunnel  1002  and is disposed below the tunnel  1002  such that the bottom of the cab  40  rests on, and is supported by, the front portion  906  of the frame extension  918 . 
     According to an exemplary embodiment, as shown in  FIG.  13   , the first side  1004  of the cab  40  is configured to accommodate an operator in a seated position. In such an embodiment, the seat support  1022  of the seat  1010  is substantially horizontal such that a person sitting on the seat  1010  does not need additional support to remain on the seat  1010  (e.g., feet do not need to be on the floor to keep the person in the seat). In some embodiments, the second side  1006  is configured to accommodate an operator in a seated position. In some embodiments, the first side  1004  is configured to accommodate an operator in a seated position and the second side  1006  is configured to accommodate an operator in a non-seated or standing position (see, e.g.,  FIG.  11   ). 
     In some embodiment, the first side  1004  includes a multi-step entry. The multi-step entry may include a plurality of steps. For example, the multi-step entry may include a first step  1203  and a second step  1204 . A first step height  1206  may be defined by a distance between the ground  1112  and the first step  1203 . A second step height  1208  may be defined by a distance between the first step  1203  and the second step  1204 . According to an exemplary embodiment, the first step height  1206  is substantially equal the second step height  1208  (e.g., +/−0.5 inches). The approximately equal distance between both the ground  1112  and the first step  1203 , and between the first step  1203  and the second step  1204  provides an ergonomically efficient entry for an operator entering the first side  1004  of the cab  40 . In one embodiment, the first step height  1206  is about 15 inches and the second step height  1208  is about 15 inches. In other embodiments, the sides  1004 ,  1006  are configured for a seated position with a single-step entry. 
     In one embodiment, the second step  1204  extends throughout at least a portion of the cab  40  to define a floor  1212 . A person entering the cab  40  may stand on the floor  1212  or may rest their feet on the floor  1212  when in a seated position. When in a seated configuration, a pedal  1210  for controlling a subsystem of the vehicle  10  (e.g., gas pedal, brake, clutch, etc.) is disposed above the floor  1212  at a location where a user can use their foot to actuate the pedal  1210 . According to an exemplary embodiment, the second step  1204  is disposed at an height that is below the top of the front portion  906  of the chassis  20 , and is therefore below the top  1106  of the tunnel  1002 . In one embodiment, a height  1214  of the floor  1212  is approximately 30 inches measured above the ground  1112 . The height  1214  of the floor  1212 , and all of the heights described herein relative to the ground  1112 , may be measured in an unloaded bare chassis condition. 
     According to another exemplary embodiment, as shown in  FIG.  14   , the second side  1006  of the cab  40  is configured to accommodate an operator in a non-seated or standing configuration. In such an embodiment, the seat support  1022  of the seat  1010  on the second side  1006  is oriented at an angle such that a person can be in a more upright position (e.g., not arranged parallel to the ground  1112 ) . The standing configuration may include the person supporting themselves with their feet on the floor  1212  of the cab  40 . In some embodiments, the first side  1004  is configured to accommodate an operator in a non-seated position. In other embodiments, neither side  1004 ,  1006  is configured to accommodate an operator in a non-seated position. In other embodiments, both sides  1004 ,  1006  are configured to accommodate an operator in a non-seated position. 
     According to an exemplary embodiment, the second side  1006  configured for a non-seated position includes a single-step entry. In one embodiment, the single-step entry includes the first step  1203  and not the second step  1204 . The height  1206  of the first step  1203  may be defined by the distance between the ground  1112  and the first step  1203 . In one embodiment, the first step  1203  extends throughout at least a portion of the cab  40  to define the floor  1212 . In such an embodiment, the height  1206  is the same as the floor height  1214 . When in a non-seated configuration, a pedal  1210  for controlling a subsystem of the vehicle  10  (e.g., gas pedal, brake, clutch, etc.) is disposed above the floor  1212  at a location where a user can use their foot to actuate the pedal  1210 . According to an exemplary embodiment, the first step  1203  is disposed at an height below the top of the front portion  906  of the chassis  20 , and therefore is below the top  1106  of the tunnel  1002 . In one embodiment, the floor height  1214  is approximately 15 inches measured from the ground  1112 . In other embodiments, the second side  1006  includes a multi-step entry. 
     According to an exemplary embodiment, the bottom of the cab  40  includes a plurality of sections. In one embodiment, the bottom surface  1104  of the cab  40  includes two sections, shown as flat portion  1302  and angled portion  1304 . The flat portion  1302  includes the area used as the floor  1212  or the first step  1203 . The flat portion  1302  is substantially planar such that it provides a flat surface for an operator to stand on to enter the cab  40 . In some embodiments, the angled portion  1304  is in front of the flat portion  1302  (e.g., closer to a grill, a front bumper, or a headlight of the cab  40 ). In some embodiments, the angled portion  1304  is oriented at an acute angle with respect to the flat portion  1302 . In some embodiments, the angled portion  1304  has an angle of approach, shown as angle  1306 . The angle  1306  may be approximately 15 degrees. 
     In some embodiments, the cab  40  includes an overhang, shown as front overhang  1308 . The front overhang  1308  may be measured from a front axle  50  to a bumper, shown as front bumper  1310 . In one embodiment, the front overhang  1308  is less than or equal to about 74 inches. 
     In some embodiments, the seat configuration of the cab  40  can switch between a seated configuration ( FIG.  13   ) and a non-seated configuration ( FIG.  14   ). A plurality of systems or components may move in order to switch between a seated and a non-seated configuration. In some embodiments, the seat  1010 , the second step  1204 , and the pedal  1210  are reconfigured or moved to accommodate a different configuration. For example, the seat support  1022  may pivot between a substantially horizontal orientation (e.g., approximately parallel to the ground  1112 ) and a sloped orientation (e.g., not parallel to the ground  1112  where a front of the seat support  1022  is arranged closer to the floor  1212 ). In one embodiment, the seat  1010  can include a mechanism (e.g., button, lever, switch, etc.), or a combination of mechanisms, that allow a user to manually change the orientation of the seat  1010 . Changing the orientation of the seat may include moving portions of the seat  1010  (e.g., tilting the seat support  1022  to be oriented at an angle) or removing or replacing elements of the seat  1010  (e.g., taking off or replacing seat cushions). In another embodiment, the cab  40  can include an automatic mechanism that automatically changes the orientation of the seat  1010  based on an input from a user. In one embodiment, the automatic mechanism includes storing user preferences in a computer system such that the seat can automatically reorient itself to a predefined position based on an input from the user (e.g., the user pushes a button and the seat  1010  moves to a preferred sloping angle previously defined by the user). When switching between a seated configuration and a non-seated configuration, all components of the seat  1010  may be adjustable (e.g., the back rest  1020 , the seat support  1022 , an armrest, a head rest, etc.). Components of the cab  40  that are not a part of the seat  1010  may also be adjustable (e.g., the steering wheel, pedals, controls, etc.). 
     According to an exemplary embodiment, to switch between a seated configuration and a non-seated configuration, the second step  1204  may move between an active position and a collapsed position. In the active position, the second step  1204  provides a floor  1212  for the cab  40 . The floor  1212  is configured to support the weight of the user at an height above the first step  1203 , wherein the height is more than just a thickness of the material of the second step  1204 . In such an embodiment, the pedal  1210  for controlling the vehicle  10  is disposed above the second step  1204 . In the collapsed position, the second step  1204  is removed from the cab  40  such that the first step  1203  provides the floor  1212  for the cab  40 . In one embodiment, removing the second step  1204  from the cab  40  includes taking the physical step out of the vehicle  10 . In another embodiment, removing the second step  1204  from the cab  40  includes swinging the second step  1204  from a horizontal position to a vertical position such that an operator can no longer step on the second step  1204 . In another embodiment, removing the second step  1204  includes collapsing the second step  1204  such that it sits flat on top of the first step  1203 . 
     According to an exemplary embodiment, to switch between a seated configuration and a non-seated configuration, the pedal  1210  may move between a lower position and a higher position. The pedal  1210  may be in the higher position when in the seated configuration. The pedal  1210  may be in the higher position when the second step  1204  is in the active position. The pedal  1210  may be in the lower position when in the non-seated position. The pedal  1210  may be in the lower position when the second step  1204  is in the collapsed position. In another exemplary embodiment, a cab  40  may include a plurality of pedals  1210 . For example, a first pedal  1210  may be configured to be used when in the seated configuration and a second pedal  1210  may be configured to be used when in the non-seated configuration. 
     In general, either side  1004 ,  1006  of the cab  40  may define the seated position/configuration or the non-seated position/configuration. Regardless of the seat configuration, the seat  1010  can be adjusted and moved to increase comfort of an operator. In some embodiments, the seat  1010  can slide longitudinally (e.g., forward and backward) to provide more or less distance between the seat  1010  and the front of the cab  40 . In one embodiment, the seat  1010  can slide between about 8 inches and about 9 inches, or about 8.7 inches. In other embodiments, the seat  1010  includes a vertical suspension (e.g., can travel up and down when on uneven roads, etc.). In some embodiments, the seat  1010  has a vertical suspension travel of about 6 inches. In other embodiments, the seat  1010  can recline (e.g., an angle of the back rest  1020  can change). In some embodiments, the seat  1010  can recline about 13 degrees. 
     According to an exemplary embodiment, as shown in  FIG.  15   , the cab  40  includes at least one side  1402 . The side  1402  may include at least one door, shown as door  1404 . In one embodiment, the door  1404 , or a portion thereof, may be formed via a stamping process. In other embodiments, the door  1404  may be formed by other processes (e.g., molded, pressed, etc.). The door  1404  facilitates selective access to the cab interior  42  from outside of the vehicle  10 . In some embodiments, the door  1404  comprises the entire side of the cab  40 . In other embodiments, the side  1402  comprises a plurality of sections. According to an exemplary embodiment, the side  1402  includes a first portion (the door  1404 ) and a second portion, shown as wall  1406 . In an exemplary embodiment, the door  1404  comprises a majority of the surface area defined by the side  1402 . In other embodiments, the door  1404  comprises no more than half of the surface area of the side  1402 . 
     The door  1404  may be configured to move between an open position and a closed position. In some embodiments, the door  1404  moves by rotating about a vertical axis, shown as axis  1408 . The axis  1408  may be coupled with a front edge of the door  1404  or a back edge of the door  1404 . In some embodiments, the door  1404  swings inward to open the cab  40 . In other embodiments, the door  1404  swings outward to open the cab  40 . When rotating about an axis, the door  1404  may use piano hinges that are coupled to an edge of the door  1404 . The piano hinges may be forward or backward hinges. In other embodiments, the door  1404  uses other hinges. In other embodiments, the door  1404  moves by rotating about a different axis (e.g., horizontal, 45 degree, etc.). In other embodiments, the door  1404  moves by being removed from the cab  40  and replaced back onto the cab  40 . In other embodiments, the door  1404  moves by sliding along a rail or track. 
     In some embodiments, the wall  1406  is stationary. The wall  1406  may provide a seal with the door  1404  when in the closed position. In other embodiments, the wall  1406  is not stationary. The wall  1406  may be configured to move between an open position and a closed position. In some embodiments, the wall  1406  moves similarly to the door  1404  (e.g., if the door  1404  rotates about an axis, the wall  1406  rotates about an axis). In other embodiments, the wall  1406  moves different than the door  1404  (e.g., if the door  1404  rotates, the wall  1406  slides). In some embodiments, movement of the wall  1406  is independent from the movement of the door  1404 . In other embodiments, movement of the wall  1406  is dependent on movement of the door  1404  (e.g., the door  1404  must open before the wall  1406  can open). In other embodiments, movement of the door  1404  is dependent on movement of the wall  1406 . 
     In some embodiments, the door  1404  has a width, shown as door width  1410 . The door  1404  may have a plurality of widths. In one embodiment, the door width  1410  refers to the widest part of the door  1404 . In some embodiments, the door width  1410  may be less than or equal to 36 inches wide. In some embodiments, the door  1404  is one continuous portion. In other embodiments, the door  1404  has a plurality of portions. According to an exemplary embodiment, the door  1404  has a first portion, shown as top portion  1412 , and a second portion, shown as bottom portion  1414 . In some embodiments, the top portion  1412  is taller than the bottom portion  1414 . In other embodiments, the top portion  1412  is shorter than the bottom portion  1414 . In other embodiments, the top portion  1412  has the same height as the bottom portion  1414 . In other embodiments, the plurality of portions are arranged differently (e.g., side by side). 
     According to an exemplary embodiment, the top portion  1412  includes at least one window  1416 . The at least one window  1416  may be thinner than other components of the door  1404  (e.g., door frame, armrest, etc.) such that the window  1416  provides more room in the cab interior  42  than the other components of the door  1404  (e.g., more clearance room for the operator next to the window  1416  than next to the door frame). 
     In some embodiments, a majority of a surface area of the top portion  1412  is comprised of the at least one window  1416 . In one embodiment, the whole top portion  1412  comprises at least one window  1416 . In such an embodiment, the top portion  1412  may include a perimeter  1418 . In some embodiments, the perimeter  1418  is as thin as an inch wide. In other embodiments, the perimeter  1418  is thicker than an inch. In other embodiments, the perimeter  1418  is thinner than an inch. In other embodiments, a majority of the surface area of the top portion  1412  does not comprise a window  1416  (e.g., solid wall). In another embodiment, the top portion  1412  includes a plurality of windows  1416 . At least one of the plurality of windows  1416  may be configured to open and close based on operator input. The input may be electronic (e.g., the window  1416  is electrically controlled by a switch) or manual (e.g., the window  1416  is manually controlled by a handle). In other embodiments, none of the plurality of windows  1416  are configured to open and close. 
     In some embodiments, each of the plurality of windows  1416  may have a perimeter  1418 . Each perimeter  1418  may be a different thickness. In other embodiments, each perimeter  1418  is the same thickness. In some embodiments, a window  1416  is positioned rearward on the door  1404  to provide extra clearance (e.g., elbow and shoulder clearance) for the operator. The window  1416  positioned rearward on the door  1404  may also provide better visibility for an operator. 
     According to an exemplary embodiment, the bottom portion  1414  of the door  1404  includes at least one window  1416 . In some embodiments, a majority of a surface area of the bottom portion  1414  is comprised of the at least one window  1416 . In one embodiment, the whole bottom portion  1414  is comprised of the at least one window  1416 . In such an embodiment, the bottom portion  1414  may include a perimeter  1418 . In other embodiments, a majority of the surface area of the bottom portion  1414  does not comprise a window  1416 . In other embodiments, the bottom portion  1414  includes no windows  1416 . 
     In some embodiments, the wall  1406  includes at least one window  1416 . In some embodiments, a majority of a surface area of the wall  1406  is comprised of the at least one window  1416 . In one embodiment, the whole wall  1406  is comprised of the at least one window  1416 . In such an embodiment, the wall  1406  may include a perimeter  1418 . In other embodiments, a majority of the surface area of the wall  1406  does not comprise a window  1416 . In other embodiments, the wall  1406  includes no windows  1416 . 
     In some embodiments, the door  1404  includes an opening mechanism, shown as opening mechanism  1420 . The opening mechanism  1420  may be any mechanism configured to keep the door  1404  in a closed position when activated, and release the door  1404  from the closed position when deactivated. Activation and deactivation of the opening mechanism  1420  can apply to either keeping the door  1404  in the closed position or releasing the door  1404  to move into an open position. In one embodiment, the opening mechanism  1420  is a handle. In other embodiments, the opening mechanism can be a lever, a button, a switch, a toggle, a latch, a knob, a handle, etc. In some embodiments, the opening mechanism  1420  is disposed on the top portion  1412  of the door  1404 . In another embodiment, the opening mechanism  1420  is disposed on the bottom portion  1414  of the door  1404 . In another embodiment, the opening mechanism  1420  is disposed on the wall  1406 . The opening mechanism  1420  may be placed anywhere on the side  1402  of the cab  40  such that it controls the movement of the door  1404  between the open position and the closed position. 
     As utilized herein with respect to numerical ranges, the terms “approximately,” “about,” “substantially,” and similar terms generally mean +/−10% of the disclosed values. When the terms “approximately,” “about,” “substantially,” and similar terms are applied to a structural feature (e.g., to describe its shape, size, orientation, direction, etc.), these terms are meant to cover minor variations in structure that may result from, for example, the manufacturing or assembly process and are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims. 
     It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples). 
     The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic. 
     References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure. 
     The hardware and data processing components used to implement the various processes, operations, illustrative logics, logical blocks, modules and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some embodiments, particular processes and methods may be performed by circuitry that is specific to a given function. The memory (e.g., memory, memory unit, storage device) may include one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage) for storing data and/or computer code for completing or facilitating the various processes, layers and modules described in the present disclosure. The memory may be or include volatile memory or non-volatile memory, and may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. According to an exemplary embodiment, the memory is communicably connected to the processor via a processing circuit and includes computer code for executing (e.g., by the processing circuit or the processor) the one or more processes described herein. 
     The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions. 
     Although the figures and description may illustrate a specific order of method steps, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above. Such variation may depend, for example, on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations of the described methods could be accomplished with standard programming techniques with rule-based logic and other logic to accomplish the various connection steps, processing steps, comparison steps, and decision steps. 
     It is important to note that the construction and arrangement of the vehicle  10  as shown in the various exemplary embodiments is illustrative only. Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. For example, the cab  40  of the exemplary embodiment shown in at least  FIGS.  10 - 15    may be incorporated into the refuse vehicle  100  of the exemplary embodiment shown in at least  FIG.  3   . Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.