Side-facing seats mounted above wheel wells are a decades-old, transit industry tradition. The reasons often cited for this configuration include:
- Side-facing seats increase crush capacity, accommodating more standees
- Side-facing seats provide more room for riders with packages
- Side-facing seats optimize passenger comfort for those sitting above wheel wells – particularly taller adults whose knees might otherwise abut their chins
- Some passengers simply like them
- Side-facing seats in front facilitate better visibility of the passenger compartment by the driver
While there may be some validity to each of these claims, such validity is extremely limited. In contrast, side-facing seats present a number of safety problems, not to mention operating, institutional and liability issues which accompany them. In truth, most passengers do not like side-facing seats – for a range of reasons including privacy, touching bodies, and sliding together during acceleration and deceleration. The addition of standees’ heads sticking up in the front of the bus, on the curb side, obstruct the driver’s view of the rear stepwell and convex mirror above it through the driver’s interior, rear-view mirror. Most importantly, such configurations waste opportunities for solutions and design improvements which new products are beginning to demonstrate. A number of important institutional and product development changes suggest that the practice of installing side-facing seats on transit buses – over wheel wells or anywhere else – should be seriously revisited.
Common and Uncommon Accident Scenarios
Two accidents illustrate different problems which such seating configurations create:
- A paratransit vehicle containing convertible, perimeter seating (which accommodated 11 seated passengers, four wheelchairs, or some combination in between) provides enormous flexibility in special paratransit service. Since such a configuration can easily be installed in a mid-size van (e.g., Ford Econoline, RAM 350, etc.), costs for such capacity and flexibility are relatively low compared to many alternatives. Deploying a fleet of such and other vehicles, this author’s former 70-vehicle paratransit fleet was often filled to 90 percent of seating and wheelchair capacity during the heaviest part of its runs. One day, a driver who presumably fell asleep at the wheel, ran through a “T” intersection and crashed, head-on, into a pole. His single remaining passenger on-board, an ambulatory individual, was properly seat-belted into his perimeter seat. Upon impact, the passenger’s head and upper torso were propelled toward the front of the vehicle, cracking his spine practically in two, rendering him a virtual quadriplegic.
- A transit bus weaving in and out of automotive and trolley traffic stopped suddenly when cut off. An elderly passenger was seated in the first aisle-side, forward-facing seat immediately behind the side-facing bench seat behind the driver. When the bus braked, she was jettisoned out of her seat into the farebox and windshield.
These scenarios demonstrate two cardinal principles of side-facing seats:
- They are dangerous for those seated in them
- They are dangerous for those seated near them
As anyone who has ever played “Simon Says” well knows, one can touch his or her toes quite easily. However, only a special contortionist, gymnast or ballerina can do this bending sideways. As a consequence, occupant restraints often create or exacerbate injuries when the crash pulses lie in perpendicular or oblique planes. This reality recently led to a four-year study and crash-testing project conducted by NHTSA to examine alternatives to compartmentalized, school bus-certified seating systems – which face forward – since such an approach provides little or no protection in oblique or lateral impacts, respectively. Seats already not facing forward provide no protection in any accident orientation.
This latter point, and the principle illustrated by the second example above, stem from the fact that one of the elements that renders a seat safe is the seat back in front of it. This is the essential principle behind the installation of modesty panels in buses – although transit buses often erect such barriers only around stepwells.
Apart from exposing passengers to serious injuries, side-facing seats expose both passengers seated in them and standees alongside them to a plethora of other, generally less severe, ones. Without regularly-spaced seat backs to grab onto, standees have one less tool to grasp and help them balance. Further, they are more likely to fall onto the side-facing seated passengers adjacent to them than they would onto forward-facing seated passengers (at least the forward-facing passenger seated on the window-side). Similarly, standees’ purses, briefcases, laptops and other carry-ons are, at minimum, a nuisance to side-facing seated passengers, but also more likely to injure them – possibly severely – in a collision, and to a lesser degree from the normal forces of acceleration, deceleration, braking and turning: While standees may secure themselves via grab handles and stanchions, their carry-ons are rarely secured in similar fashion.
To the degree that “grocery bag syndrome” remains another traditional justification for side-facing seats, one must recognize that such objects would effectively be placed in the aisles. While stowing bags and packages is somewhat more of an inconvenience for forward-facing seated passengers, at least this positioning would keep their belongings out of the way of passengers moving in both directions through the aisle – and especially on crowded buses, unlikely or unable to look down as they move about trying to avoid bumping into fellow-passengers.
Finally, side-facing seats are mounted higher up than their forward-facing counterparts. As a result, a smaller percentage of riders can touch the floor, resulting in an aggravated imbalance for these individuals. (This is a particular concern for schoolchildren.) Worse, and particularly with no seat backs in front of them, such passengers not only possess a greater risk of falling out of their seats during turns (much less side or oblique impacts, or from the rebounding which occurs in almost every accident scenario), but have a greater distance to dropif and when they do. Instead of falling into a cushioned seat back or modesty panel, they would likely fall into some standee’s knees or hips – if they were not lucky enough to simply sprawl onto the floor, possibly striking their heads on vertical stanchions or side-facing seat frames on the opposite side of the aisle.
New Issues, New Opportunities
The expanded presence of three-point, occupant restraint devices in buses raises more complex seating issues, even for forward-facing seats. Three-point occupant restraint systems, along with newly-developed, contoured seats to accompany them, will soon be required for school buses in California; similar legislation is being revisited in Florida and Louisiana. Few U.S. motorcoaches contain lap belts, while three-point belts are required on motorcoaches in most European countries. Lap belts, in particular, contain considerable downsides – particularly for school buses. Among these shortcomings, the “envelope of restraint” for these devices is less than the spacing between the seat backs. As a result, lap belts simply convert the passenger’s waist to a fulcrum – and accelerate movement of the passenger’s head into the seat back in front.
However, three-point systems do not possess this characteristic, and thus comprise a supplemental safety system to compartmentalized seating without compromising the effectiveness of the latter. Combined with compartmentalized seating (including seat-spacing in accordance with it) – effectively a “passive” restraint system – occupant restraint systems do not leave passengers vulnerable if these systems are not used. (New York State – one of two states which require the installation of lap belts on school buses – has the peculiar distinction of not requiring their usage.) As a result of all this, forward-facing seats are becoming even safer, and side-facing seats less safe by comparison. Further, as illustrated above, the application of similar technology to side-facing seats makes them even more dangerous than they already are. In simple terms, the continued practice of installing side-facing seats is effectively immune to improvements in seating safety, and makes they comparatively less safe as other seating system improvements evolve.
One fascinating anomaly in the development of bus technology relates to the profusion of low-floor buses, including the virtual disappearance of full-size and articulated, high-floor transit buses from the U.S. and Canadian transit markets. While the low floor configurations obviously facilitate accessibility, at least one study has demonstrated that boarding and alighting time for ambulatory passengers is pretty much the same for both high- and low-floor models. At the same time, the wheel wells in such buses are even more disruptive, and more difficult to mount seats of any kind onto without experiencing more exaggerated versions of many of the problems sited above, particularly when these seats are side-facing.
In contrast, many bus manufacturers have made ingenious uses of this space, even if these uses preclude using the space for seating. One of the impacts of these efforts, particularly on articulated buses, is the almost endless array of seating configurations available. One manufacturer even mounts seats on the rotating disc lying between articulated sections! As noted, more than one manufacturer has mounted seats atop these raised wheel wells – generally, side-facing, single bucket seats. As these seats involve single positions, and generally contain arm rests or some form of modesty panel on both sides, they are safer in some ways than the side-facing bench seats mounted over the lower wheel wells on conventional, high-floor transit buses.
Developments in seat convertibility which coincided with the ADA have demonstrated even more versatility. As a frame of reference, forward-facing flip-up seats were not available – even on vans and minibuses – at the time the first accident noted above occurred. Most interesting of such developments are the track seating applications employed recently by two motorcoach manufacturers. Largely a response to the otherwise reduction in ambulatory seating capacity from the inclusion of a lift, lift door and securement positions, this application essentially involves mounting curb-side coach seats (or a section of them forward and aft of the rear door) onto the same hexagonal, aircraft-industry tracks used for wheelchair securement.
Thus, when no wheelchair occupants are on board, not only are their securement positions occupied by regular ambulatory seats, and at the same spacing intervals, but these same seats are also located in front of the lift door. Thus, without wheelchair occupants, the coach maintain full, normal and uninterrupted ambulatory capacity. To accommodate a wheelchair occupant, a few rows of curb-side seats are simply scrunched forward and/or rearward – depending on the number of wheelchairs to be accommodated. Of course, this approach is not practical for transit applications, since the rear doors are used to alight ambulatory passengers. Nevertheless, it demonstrates the versatility in design possible when one removes side-facing seats over wheel wells from the equation.
In properly characterizing the mythology about adult passengers loathing school bus seating largely because of the wheel well seats (as well as the spacing intervals, and the narrow aisles which 102-inch wide transit buses do not contain), the comfort-obsessed motorcoach industry rarely expresses concern for those wall-side passengers who, frankly, are lucky enough to get a built-in, au natural, footrest. (In other words, transit buses with forward-facing seats over wheel wells would not have to contain signs saying “wheel well;” signs could state “foot rest.”Little effort would be needed to enhance the exterior surfaces for this purpose.)
Special Problems for Special Users
One of the ironies of side-facing seats rarely lost on plaintiff’s attorneys is that ambulatory elderly and disabled passengers – whose need to ride seated is institutionalized in the requirement for priority treatment – either use, or are directed toward, the least safe seats on the bus:
- On crowded buses, drivers ask passengers seated in side-facing seats to yield them to the elderly or disabled passengers who have just boarded.
- On un-crowded buses, because they have more difficulty walking through the bus (particularly when it is moving), these same individuals often choose the aisle-side, forward-facing seats directly in back of the side-facing seats – seat positions even more dangerous than the side-facing seats. (This is because the inertial forces which propel passengers forward during deceleration and braking are usually greater than the centrifugal forces they experience during turning.)
To the degree such passengers are placed in side-facing seats, their ability to sustain a seated position throughout changes in inertia and centrifugal forces is less than that of other passengers (the reason that seating elderly and disabled passengers is so important in the first place). Similarly, they are less able to remain in forward-facing seats which are not compartmentalized by seat backs in front of them, particularly in the aisle-side seat.
Safety and Liability
Insofar as liability goes, one can recognize that such observations are difficult to rebut. In a courtroom, with an elderly or further-maimed, disabled passenger as the centerpiece, the weak rationales for side-facing seats cited above are likely to be wholly ineffective – or at best, weak and trite. At minimum, they suggest that the defendant bus operator exercised a trade-off of safety for comfort and/or capacity in its development of vehicle specifications. An informed plaintiff’s attorney, through expert testimony, will quickly demonstrate that such a configuration fails to significantly improve either – if it effects them at all.
Another important problem concerns schoolchildren riding as standees. While ambulatory schoolchildren are likely to possess better balance than many adults (insofar as standing on a moving vehicle), they rarely possess better judgment. Their accommodation by greater “crush capacity” is offset by the safety compromises they experience as a result. To the degree side-facing seats permit more standees – a position which is debatable when one thinks it through (as per the discussion below) – the U.S. litigation environment is not conducive to a trade-off of safety for performance improvement or cost reduction. But this environment is oversensitive to these trade-offs when they affect schoolchildren – all of whom use forward-facing seats on their yellow school buses costing a fourth or a fifth of most modern transit buses of equal size.
A similar problem involves the use of side-facing seats by schoolchildren. This is largely because school buses do not contain them. Further, every school bus seat without one in front of it contains a modesty panel constructed precisely the same as the seat back otherwise missing. Given the construction typical of most transit bus seats, much less transit bus modesty panels/crash barriers, the protection these riders receive in side-facing seats is hard to equate with that which they would be afforded in most forward-facing transit seats, much less heavily-padded, compartmentalized, forward-facing school bus seats. These distinctions are not often lost in the courtroom.
Mythology Versus Reality
Apart from the obvious safety deficiencies of side-facing seats, they provide virtually no benefits, despite a considerable number of assumptions to the contrary:
Comfort. Anyone who has ridden in a side-facing seat recognizes its characteristics. Excessive centrifugal forces which otherwise shift passengers slightly sideward, on forward-facing seats, during vehicle turning movements, may occasionally spill an aisle-side passenger into the aisle from a violent turn in the opposite direction. This is rare largely because these passengers can grasp the seat back in front when they begin to experience these forces.
In contrast, passengers in side-facing seats are affected continually by significant forces in acceleration and deceleration. In the bench-type, side-facing seats common to most transit buses (with the exception of a few new variations noted above), passengers are continually scrunched up against one another. In turns, they can be pitched forward from their seats almost as easily as they might otherwise be pitched sideward in forward-facing seats. These discomforts far exceed those associated with forward-facing seats mounted above wheel wells (only discernable inconveniences for tall individuals). To the degree such discomfort is even worth noting, a simple sign on the wall stating “Wheel Well” should alert any would-be passengers to it.
Versatility. Like comfort, the versatility associated with side-facing seats is an illusion: When the extra room so valued is actually needed, this is only because seat positions are full. But when side-facing seats are occupied (as they would be if the bus is full), the passengers’ knees and feet protrude almost as far into the aisle as their shoulders would were they seated in an aisle-side, forward-facing seat. In other words, four passengers seated on a side-facing bench – which requires essentially the same span as two forward-facing seats – occupy pretty much the same space. In contrast, their relative safety is dramatically different.
Regarding the myth of grocery bags, which side-facing seats presumably accommodate, one suggestion for resolving this need – particularly given the configuration of low-floor buses – is to place them on the wheel wells! Irony aside, such an approach would not only alleviate back injuries and slip-and-falls by these package’s owners (who would no longer have to place them on, and pick them up from, the floor), but alleviate obstacles over which non-bag-owners may trip, particularly on crowded buses where objects lying on the floor are obscured. Placing objects on surfaces or racks atop wheel wells is an approach typically employed by low-floor airport trams as well as high- and low-floor shuttle buses – vehicles on which many passengers routinely ride as standees. Thus, while many such buses contain mostly side-facing seats, and lie beneath much of the regulatory radar, their designers and manufacturers at least recognize the danger of accommodating standees and packages on the same surface.
Accessibility. Accessible transit buses typically contain wheelchair securement positions beneath side-facing, flip-up bench seats. As a result, one might conclude that the side-facing seating configuration contributes to the wheelchair accommodations. In truth, forward-facing flip-up seats emerged on the U.S. public transportation market in the late Eighties, appearing first on ramp-equipped, low-floor minivans. The devices providing this vehicle’s convertibility were a removable front seat (and storage capacity for it behind the rear-most bench seat, via a rear door) and a flip-up, forward-facing bench seat hinged on the street-side interior vehicle sidewall. To accommodate the latter with seat backs, the seat backs also folded against the seat cushion. In truth, folding them up on transit buses would block the window view in these spots. However, as with comfort, safety is hardly a justifiable trade-off for some obscure degree of symmetry or improved visibility: With the seating positions occupied by wheelchairs, only the wheelchair occupants would be deprived of a view through the window. Common sense suggests few of them would mind or complain.
Directional Stability, Weight Distribution and Passenger Movement. Another benefit of evenly- and uniformly-configured seating arrangements is the distribution of passengers throughout the vehicle which the seating would accommodate. Uneven weight distribution creates problems when vehicles are overloaded (and thus, their suspension systems are overloaded, and their ability to counteract inertial and centrifugal forces – particularly for standees – is compromised). It also creates problems when buses are not overloaded. Among others, more aisle space surrounding unoccupied side-facing seats permits more passengers to ride in the front of the vehicle – since they all board through the front, and can alight from either the front or rear.
While certainly not creating the problem some under-utilized aircraft may encounter with uneven passenger-weight distribution, the uneven distribution of bus passengers often shifts more weight onto the front axle, changing the dynamics of the suspension system when the vehicle decelerates and brakes (since rear bus brakes are designed to engage slightly earlier than front ones, to minimize the lurches which would otherwise occur). The tendency of transit riders to arise and move toward exit doors before the bus stops not only exacerbates these problems of weight distribution, but exposes these passengers to the inertial forces of deceleration and braking (and turning, from both pull-ins and cornering to reach certain far-side stops) at the moment the front axle may be most overloaded, and the passengers most vulnerable (i.e., as unsuspecting, moving standees, not always holding onto stanchions). Further, with more passengers riding in the front, more passengers would tend to exit from the front, resulting in greater dwell times, particularly as most front stepwells do not accommodate two persons abreast, much less climbing up and down in opposite directions, pivoting around a farebox area designed for one-way movement, and frequently experiencing delays in that movement.
Marketing. Since side-facing seats are anathema to the transportation of schoolchildren, and as transit system and schoolchildren riders are increasingly in need of one another, the continued presence of side-facing seats simply compounds the already-existing deterrence which pupil transportation officials and constituents (particularly their parents) have regarding student ridership on non-school buses – much less buses where the passengers may ride as standees. But even if priority treatment were extended to schoolchildren – a problematic and unrealistic position this author is certainly not advocating – it would not address the legitimate as well as traditional safety needs and interests of this audience as long as side-facing seats were available, much less its focus, as such seats’ problems are with elderly and disabled passengers. In simple terms, side-facing seats provide just one more excuse for pupil transportation professionals to rail against the use of transit by schoolchildren.
Some of these considerations may seem petty. Even if this were so, there is no reason to debate the issue since the benefits of side-facing seats are either minimal or illusory. Whatever disbenefits are associated with forward-facing seats are more than offset by a litany of benefits.
Coordination and Consolidation
Two projects zooming onto the public transportation horizon as of this writing are NHTSA’s proposed rulemaking (docket no. NHTSA-2002-13704), and the FTA-funded A-19A project. Both projects are aimed at the development of specifications for a multi-function or multi-purpose school/activity, school-transit or “Head Start” bus.
The NHTSA version was conceived largely as a non-yellow bus (thus, a vehicle with no crossing protection and appendages), while the A-19A version was conceived largely as a school bus to be also used for other purposes (either alternating with schoolchildren or co-mingling other passengers with them). The purpose of such vehicles is largely to provide a cost-effective mode of transportation in low-density areas which might not be able to afford separate transit or pupil transportation services.
Particularly with the NHTSA version, targeted initially at smaller vehicles with GVWR’s between 10,000 and 15,000 lbs., standees are either illegal (e.g., on vehicles weighing less than 10,000 lbs. GVWR, since all their passengers must use occupant restraints) or would be rare. There are, of course, exceptions, as for example on airport or hotel shuttle vehicles. The problem with standees on vehicles of this size is that few or none of them are available with air bags – or at least not pneumatic suspension systems(i.e., the entire suspension system is designed to accommodate air bags, rather than their simply being “shoe-horned in” as a comfort feature or marketing gimmick). Regardless, the inclusion of, and focus toward, schoolchildren on both modes gives side-facing seats no place in either. As a regulatory matter, side-facing seats may not even be permitted in either mode – depending on how such technical issues are eventually resolved as these two projects unfold.
Side-facing seats offer few or no benefits, yet involve considerable problems and risks. The transit industry would be well-advised to begin phasing them out.
The industry should also consider conducting or encouraging further research to clarify the ideas and issues presented in this paper, subject them to more rigorous examination and, where possible, quantify the benefits and disbenefits of side-facing versus forward-facing seating systems, expanding upon many of the concepts examined above.