Transportation Deployment Casebook/Accessible Public Transportation

The market for handicap accessible public transportation, specifically flexible modes of transit like buses, have arguably been a public concern since the dawn of that mode of transportation. In America the first large scale demand for accessible public bus transit likely emerged following the waves of disabled veterans returning home from World War II. This surge in potential users coupled with a rapidly shrinking network of inner city trolley services created a niche in the transportation market that would take another 50 years to fill. In 1990 the Americans with Disabilities Act was passed created a federal mandate enforceable by law, that would further strengthen the steps many municipalities had taken to provide accessible public bus transit for their residents.

Quantitative AnalysisEdit

The life-cycle of the handicap accessible bus is unique in that it modified an already existing mode of transportation rather than creating an entirely new mode. The birth of this mode was not simply a response to the Americans with Disabilities Act of 1991 as one might think. The Americans with Disabilities Act only accounts for the about half of the total growth in handicap accessible buses in service as of 2006. Analysis of the data shows a likely inflection point (the time when the mode goes from growth that is constantly increasing to growing but slowly decreasing) of 1995.65, a time only a few years after the Americans with Disabilities Act was passed.

In fact this mode owes its birth to a growing market of handicapped users that pre-dates the Americans with Disabilities Act of 1991. This indicates that municipal transit agencies where recognizing the need to provide transit services to disabled citizens long before the federal mandate made by the ADA and FTA. As shown in the data in figure 1 there is a relatively steady rate of growth (the growth phase) from 1993 to 2001, although it is likely that the growth phase began prior to the 1991 ADA regulations. At the end of the curve you can see the mode begins to enter its mature phase around 2002 at which point the number of accessible buses only increases by about two thousand a year.

Figure 1

In figure 1 the regression line very accurately depicts the trajectory of the data as indicated by the R-squared value of 98.386. This model predicts the mode will reach capacity at around 74,300 accessible buses nationwide. Given the current trend of this line it is likely that this figure will be reach within the next decade however a rapidly expanding elderly population in the United States may push actual figures beyond the predicted capacity.

Qualitative AnalysisEdit

Essential Technological CharacteristicsEdit

There is a long list of characteristics and measuring associated with providing equal accessibility to bus transit users that include physical changes to equipment and instructional changes for operators and users. Part 38 of the Americans with Disabilities Act (Appendix 1) lists these and other specification as part of the accessibility standards for buses:

  • Audible & visual stop announcement (Section 38.37)
  • Safety lighting (Section 38.31)
  • Visual route identification & audible announcement (Section 38.39)
  • Harnessing, adaptable seating (Section 38.23)
  • Hand rails, railings (Section 38.23.13 & 38.29)
  • Clear paths of travel and turning(Section 38.23)
  • Right to assistance (ADAAA)
  • Kneeling buses, ramps, & lifts (Section 38.23)
  • Handicap seating policies and signs (Section 38.27)


Providing accessible buses for transit users has several benefits and drawback, for both the system and its users, some of which are clearer than others. Perhaps the clearest advantage to providing handicap accessible buses is the resolution of the moral imperative this practice provides. Because many disabled individuals rely on public transportation as their primary, and in some cases their exclusive mode of transportation, provisions for their use of this public amenity provides for the public good. It also dramatically increases the productive capacity of these individuals by providing them more flexible and reliable access to sources of employment, shopping, recreation, and other resources. It is also important to remember that these amenities provide access to public transit for those who are temporarily disabled, increasing the flexibility of the system to provide for a wider range of users.

Another important advantage is the potential to increase transit ridership. With public transportation systems across America constantly working towards increased ridership, both to cover operational costs and promote expansion of transit networks, those with permanent and temporary disabilities represented an untapped source of potential users. Knowing that mobility can be impaired in a range of ways, it is logical that a disproportionate number of this demographic group has some reduced capacity to provide directly for their own transportation, due either to physical or mental impairments. These barriers, discrimination in the job market, and other factors that economically disadvantage the disabled, make owning a specialized (adapted to enable a disabled driver) automobile even more difficult, further increasing their reliance on and need for accessible public transportation.

There are of course costs to increasing the capacity and ridership of any public transit system. The foremost drawback is the initial cost of retrofitting existing buses already in service to accommodate the disable. Additionally there are increases in costs associated with designing and building the complicated systems needed to make new modern buses and their stops handicap accessible. Increasing accessibility will also inevitably result in reductions in system efficiency, with handicapped riders requiring longer boarding times, extra time for route and stop identification, and in some instances the need for driver assistance (securing wheelchairs, etc.).

Primary MarketsEdit

The primary user market for accessible buses is those individuals with permanent physical disabilities requiring some assistance in boarding, seating, and off-loading. Other markets include those who are mentally impaired, those with temporary disabilities, the elderly, and those who have other mobility barriers such as child strollers and shopping carts. Geographically these buses tend to service the densest centers of population, typically central cities and areas of low income levels. Additionally the expansion of transit services has given rise to handicap accessible Bus Rapid Transit (BRT) bus lines extending into suburban rings.

History of Other Handicap Accessible Transit OptionsEdit

The appearance of alternative modes of accessible public transportation is unique in their collinear evolution. Since its inception, ADA regulations have required the modification of all modes of ‘public’ transportation for equal accessibility. This created an environment of rapid collinear modification that essentially impacted all modes simultaneously in the United States. Prior to ADA regulation, there was very little in the way of accessible public transit options due in large part to the high cost of retrofitting existing stations, vehicles, and other infrastructure.

Perhaps one of the most recognizable modes of handicap accessible transportation came with the advent of the van and mini-van in the 1960’s and 1980’s. The introduction a private automobile with a sizable interior space resulted in the subsequent appearance small companies that emerged to modify these vehicles for handicap use. The high cost of modifying these vans for handicap use has been a consistent barrier to access for this mode of transportation. Because of the high cost of ownership small businesses and public services emerged to provide ‘by request’ service for those who could not afford their own vehicles. Facilities with high levels of handicapped users such as nursing homes, hospitals, etc. also became early users of these limited modes of handicap transport. The limited capacity of these vehicles, often limited to a single handicapped passenger, was another limiting factor to this mode capturing more of the market.

An important emerging market trend is the coming of ‘age’ of the baby-boomer generation. As this large generation ages, their physical ability will continue to decline, a trend that will put increasing pressure on the existing accessible public transportation system. Further compounding this trend is the increasing life-span of the average American, increasing levels of obesity, and to some degree the new generation of disabled veterans emerging for the decade long War on Terror. Certainly these phenomena working in concert with local conditions will drive increases in system capacity and innovation.

Invention of the Accessible BusesEdit

The principle technological innovations for improving accessibility have focused on both physical and operational improvements to buses. Early bus modifications focused on improving movement in and out of the vehicle first with lifts and then with lowering. Early lifts were of two primary types, integrated stair assemblies and dedicated. Each of these early access technologies had drawbacks. Integrated stair lifts occupied the stair space during deployment, preventing boarding by other passengers until loading is complete. This type of lift is also difficult to deploy manually and been notorious for mechanical failures. Alternatively dedicated lifts, while being more reliable and providing simultaneous boarding capacity, occupy large amounts of space in the bus that would otherwise be used of seating. New boarding innovation has focused on level boarding. Level boarding buses use a combination of sliding ramps and air suspension to temporarily low the bus to boarding level using the ramp to compensate for large grade and slope variations.

Other technological innovations have focused on conveyance of information to and from disable riders. Stop request systems feature standardized mechanisms, multi-sensory indicators, and multiple initiation mechanisms allowing disabled users to recognize their stop, and access the indicate mechanism to convey their intent to disembark. These include but are not limited to:

  • Braille stop request button
  • Audible signals from the driver
  • Audible and visual station/stop name indicators
  • Audible and visual stop indicators
  • Multiple level stop indicator mechanisms

Signage standards for bus stops are also required to comply with ADA standards as shown in figure 2.

Figure 2

Integration has also been a key sector of innovation for making accessibility improvements to buses that do not sacrifice efficiency. For example most new buses have handicap seating areas that are integrated into the seating configuration of the bus. This provides a handicap spot when needed and allows for standard seats to be folded down in place when the area is not in use for handicap seating.

Policy changes have also made for more efficient and standardized boarding and seating for all users. The gentlemen’s rule is now a standardized policy for most transit authorities throughout the nation allowing handicapped riders to load first, disembark first, and sit in front of the bus. ADA policy also dictates that drivers are required to provide assistance for boarding, seating, stop indication, and disembarking.

All of these innovations have been geared to increase efficiency while still providing a level of service equal to the typical able-bodied user. One key distinction made by ADA regulations is that there should be no limitation to accessing public services like transportation, meaning that all users should be able to access all of the benefits of the transit service at the same level regardless of physical or mental status. The requirement to avoid differentiation in service has impaired past transit efficiency, steering many agencies towards integration of technologies and standardization of processes as a means of streamlining the accommodation process.

Early Market DevelopmentEdit

The transit market for disabled individuals was a wholly under-served market for decades. This market has several segments, each requiring specific service provision to meet ADA guidelines. Broadly these categories of users can be defined as follows:

Mobility Impaired
Primary needs include boarding and departure assistance, as well as restraint assistance
Sensory Impaired
Primary needs include stop and information indication and information
Mentally Impaired
Needs vary widely, but informational conveyance is a typical concern
Not necessarily disabled or impaired, but may need some assistance.
Needs vary, but boarding and departure assistance and seating provisions are common
Temporarily Impaired or Encumbered
Seating provisions and in some cases boarding and assistance needs are common

Functional enhancement as required by the ADA, has serendipitously provided better transit service for temporarily impaired and encumbered users by mandating technological improvements that would have not been economically justifiable in other circumstances. Similar benefits have also been extended to the elderly as a result of ADA requirements making public buses easier to enter and exit as well as providing priority seating.

The Early Role of PolicyEdit

Although guidelines from the ADA and Federal Transit Administration do not require the immediate conversion of buses, the data shows that just a few years after the Americans with Disabilities Act is passed there are very high levels of accessibility across all bus types by 1993, as seen in figure 2. This indicates that many municipalities had already begun the conversion process prior to the ADA requirements as a means of meeting the needs of local residents. This is particularly true for the smaller and more flexible buses, seen in figure 3, which had in many cases already been converted for on demand handicap transport and para-trans operations by the mid-1990s. Newer bus technologies like articulated buses had much lower levels of initial compliance with these standards, but rapid reconfiguration coupled with the mandate that new orders must meet with ADA guidelines resulted in a rapid increase in the percentage of accessible articulated buses by the year 2000.

Figure 3

Because ADA regulations are the principle driver of change for this mode of transportation, and because the United States has such a strong focus on equal rights it is unlikely that policies were derived from other modes or countries. Policy creation has instead been a continual process of innovation and refinement, often driven by the users (disabled users) who encounter new or persistent obstacles in their day to day activities. ADA policies are created through an iterative process which looks like this (ADA, 2010):

  • A user, agency, or other entity encounters an obstacle or anticipates a future problem and initiates the formal process.
  • Guidelines, regulations, or changes are then published in the Federal Register
  • These guidelines, regulations, and changes are then subject to a period of public comment and agency review.
  • Final Rule is published in the Federal Register.

Nearly all accessibilities policies are sanctioned by government through ADA regulations. As the mode of accessible buses continues into maturity operational changes and technological advancements can arise from embedded policies as long as they comply with federal regulation. These regulations apply to any entity that is receiving Federal financial assistance from the Department of Transportation or any public entity that provides designated public transportation or intercity or commuter rail transportation, any private entity that provides specified public transportation; and any private entity that is not primarily engaged in the business of transporting people but operates a demand responsive or fixed route system (FTA, 2007).

Growth Phase of the Accessible Public BusesEdit

The growth in this particular mode of transportation has been almost entirely driven by public sector involvement. The high cost of technology per user in this market has been a barrier to entry for large scale deployment of accessible route-based bus transit outside the public sphere. Although the public sector is the primary market actor, private sector participants may provide services provided they follow FTA and ADA guidelines according to FTA sections 37.7 which states that requirements apply to all over-the-road buses acquired by public entities or by private contractors to a public entity (FTA, 2007). This and other details in sections 37 and 38 of the FTA/ADA regulations are important to the evolution of this transit mode because of their use in litigation action against both public and private entities.

Lawsuits against both public and private bus service providers have had many functional impacts on the system as a whole. A few examples of important precedent cases for litigation against both public and private transportation providers and their importance are listed below:

Olmstead v. L.C.
Relevance: The Americans with Disabilities Act (ADA) bars the unnecessary segregation of people with disabilities in state institutions
Larry Beauchamp -vs- Los Angeles County Metropolitan Transit Authority
Relevance: A case where plaintiff claimed ADA discrimination from an on-demand transit service offered by a private company as a supplement to the regular transit service provided by a city.

Litigation has become a primary mechanism for ADA standards enforcement for several reasons. First the scope of ADA regulation is massive and would be impossible to enforce through agencies monitoring alone. Second the ADA regulatory system can only be called on to ensure that initial design standards are met, any changes after initial inspection typically require a complaint report to trigger additional inspection and corrective action. Third the ADA regulatory system by its nature has built in compliance monitors in the individuals it protects. Users conducting their day to day activities function much more efficiently as standard monitors because of anonymity (not associated directly with the ADA or FTA), local knowledge, and repeated exposure to chronic offenders.

Although this monitoring function acts as an effective monitoring for compliance mechanism it has also become a contentious issue over what has been viewed by some parties as over-litigation. Business and small business owners maintain that this litigation is placing undo financial strain on their business do to legal and compliance costs. In many instances their chief complaint is that the regulations are too complex and that compliance is difficult and expensive to achieve and maintain, especially for small businesses that are unfamiliar with ADA regulations. These costs represent a significant barrier to entry for many private agencies attempting to provide regular or supplementary on-road transportation services.

Maturation of Accessible Bus TransitEdit

As the mode has matured and litigation concerns persist, attempts by the ADA, FTA, and private consultancies has been made to provide design and regulatory guidance for transit system operators in order to alleviate some of the complexities associated with the ADA and FTA regulation. Additionally transit agencies themselves have in many cases created internal positions for ADA accessibility experts to ensure that all facets of the transit system comply with regulation. Enforcement and maintenance of standards have also become inter-agencies roles as transit and planning authorities educate operators, assessors, and transit police on ADA requirements.

Although the standardization of accessibility technologies has made systems easier to use and understand these same standards have also resulted in the stagnation of technological innovation in signaling, signage, and loading mechanisms. This standardization has undoubtedly permeated bus manufactures seeking economies of scale. This combined with a relatively saturated market for accessible buses creates an environment which does not promote innovation in these technologies. That said, the focus on expanding public transit networks in major metropolitan areas coupled with a figure of one fifth of the America’s population being disable (a number that is projected to continue to rise in the coming years) it is quite probable that we may see a market revitalization in the coming years.


While the accessible bus market is relatively mature in its life cycle there are still steps to be made in improving the system. One key area of improvement is a more complete provisioning for the conveyance of information. Specifically there are no regulations governing the conveyance of transit system specific information such as route and scheduling information. This makes understanding the operation of system routes more difficult or impossible for those who are visually impaired. Currently most systems rely on interaction between the driver and the disabled individual to convey bus number, where it goes, whether the bus is on time, crowding conditions on the bus, availability of other buses nearby that may better fit the user’s needs, etc. This issue could be at least partially resolved with multi-sensory data conveyance tools. Opportunities exist to integrate these tools with other high-tech bus management systems like GPS tracking and real-time updating station schedules.

The maturity of the system, and the constant monitoring and threat of litigation has resulted in an environment that has necessitated the rapid maturation of handicap accessible buses in the U.S. Technological advancement in accessible buses has therefore been largely the result of regulatory requirements rather than market forces. The rapid rate of technological advances that punctuated early system improvements is likely to continue to decline while system operational and informational advancements are likely to yield the remainder of accessibility gains in the future for this mode.


As the average age and rate of obesity of U.S. citizens continues to climb over the next few decades it will be interesting to watch how accessible bus systems adapt to handle inevitable increases in demand over the coming decades. It may be that significant system changes will not come until the mode itself is changed in some dramatic way, i.e. double decker buses may allow for advancements in different loading system technology. Information technology may also improve system efficiency by conveying information more effectively allowing disabled rider to make more efficient system choices and transit operators to anticipate handicap user needs.


2010 ADA Standards for Accessible Design. Department of Justice, 15 Sept. 2010. PDF.

1991 ADA Standards for Accessible Design. Department of Justice, 1994. PDF.

"New or Proposed ADA Regulations." ADA Information and Technical Assistance on the Americans with Disabilities Act. Department of Justice, 8 Oct. 2010. Web. 10 Oct. 2011. <>. Nguyen, Long X., and Deborah D. Johnson. National Transportaiton Statistics. Washington DC: Bureau of Transportation Statistics, 2011. PDF.

"Part 37--Transportation Services for Individuals with Disabilities - 0726CB3D4779478E8B60DA001A4ABF47." Transportation Services for Individuals with Disabilities. Federal Transit Administration, 1 Oct. 2007. Web. 9 Oct. 2011. <>.

"Part 38--Accessibility Specifications for Transportation Vehicles - 0726CB3D4779478E8B60DA001A4ABF47." Accessibility Specifications for Transportation Vehicles. Federal Transit Administration, 1 Oct. 2007. Web. 10 Oct. 2011. <>.

United States. U.S. Department of Transportation. Federal Transit Administration. Transportation for Individuals with Disabilities. U.S. Department of Transportation, 6 Sept. 1991. Web. 9 Oct. 2011. <>.