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Bureau of
Research Note

September 2002

Common Vehicle Modifications for Persons with Disabilities

    America's highways and roads are dominated by personal motor vehicles, such as cars, trucks, and sport utility vehicles (SUVs). People love the flexibility of such vehicles to travel where and when they want without having to schedule in advance, wait at stations, or endure other constraints. Indeed, according to the Bureau of Transportation Statistics' Omnibus Survey, over 95 percent of all U.S. adult residents drive or ride in personal motor vehicles. Among adults with disabilities, 83 percent use such transportation.1  And although disabled persons need the flexibility of motor vehicle transportation as much as anyone else, they first may require vehicle modifications to accommodate their unique needs.

    Related to that topic, the National Highway Traffic Safety Administration (NHTSA) asked BTS to summarize information from a Louisiana Tech University Survey of Mobility Equipment Dealers concerning vehicle modifications for persons with disabilities. The survey was conducted in the summer of 2000, and asked respondents (2,100 mobility equipment dealers in the United States) to provide information for a one-year period (June 1, 1999 through May 31, 2000). Responses were received from 101 dealers within 35 states.2 


    The 101 dealers reported making modifications to 10,129 vehicles during the period of interest. They reported that vans (full-sized and mini) were adapted most frequently, and that vehicles were modified more frequently for drivers (5,995) than for passengers (4,134). The distribution of modifications by vehicle type and consumer (driver or passenger) is shown in Table 1.

    Table 1. Type and Number of Vehicles
    Modified by the 101 Dealers

    Vehicle Type Number of Vehicles Percent
    Sedan 1,980 19.6
    Driver 1,408  
    Passenger 572  
    Lowered floor minivan 1,229 12.1
    Driver 613  
    Passenger 616  
    "Stock" minivan 2,396 23.7
    Driver 1,913  
    Passenger 483  
    Pickup truck 501 4.9
    Driver 377  
    Passenger 124  
    SUV 452 4.4
    Driver 331  
    Passenger 121  
    Full-size van 3,571 35.3
    Driver 1,353  
    Passenger 2,218  
    TOTAL 10,129 100.0

    For the 10,129 adapted vehicles, respondents reported a total of 30,907 modifications as shown by type in Table 2.

    Table 2. Type and Number of Vehicles
    Modified by the 101 Dealers

    Modification Type Number of Modifications Percent
    Vehicle access 11,490 37.2
      Power door operators
      Wheelchair lifts
      Raised roof systems
      Raised door openings
      Lowered floor (passenger), full-size
      Lowered floor (driver), full-size
      Lowered floor conversion, mini-van
    Steering system 3,094 10.0
      Steering devices
      Reduced effort systems
      Emergency backup systems
      Removed/disconnected air bag
    Secondary controls 1,159 3.7
      Electronic control touch pads
      Parking brake extension lever
      Power parking brake
      Left hand gear selector lever
      Power gear selector
    Brake/accelerator systems 3,901 12.6
      Mechanical hand control
      Powered brake/throttle control
      Left foot accelerator
      Reduced effort brakes
      Pedal extensions
    Driver position 3,428 11.1
      Removable driver seat
      Power transfer seat
      Transfer assists
    Miscellaneous 7,835 25.4
      4-point wheelchair tie-down
      Battery protector/backup system
      Wheelchair/scooter hoist
      Suspension system modifications
    TOTAL 30,907 100.0

    The 101 dealers reported that they made the most modifications in the vehicle-access category. Within the other categories, steering devices, wheelchair or scooter hoists, and removable driver seats were also installed with some frequency.

    Cost of Modifications

    The survey did not ask for the actual cost of modifications made by the dealers. But it did ask whether the cost was paid by the consumer or by a third party such as an insurance company or rehabilitation services organization. The 101 dealers reported that about 73 percent of the modifications were paid by the individual consumer, and about 27 percent by a third party.


    The number of modifications made for people within each specified age range is shown in Table 3, regardless of whether the modifications were for drivers or for passengers. Interestingly, the number of modifications made for those aged 60 years or older exceeded those made for those between 21-35 years of age, indicating demand for vehicle modifications even into later years

    Table 3. Consumer Age for Which the
    101 Dealers Made Modifications

    Age Range Number of
    Percent of
    0-20 years 447 8.9
    21-35 years 1,159 23.1
    36-59 years 1,967 39.1
    60+ years 1,453 28.9
    TOTAL 5,026 100.0

    Driver Evaluation and Training

    The decision to install special equipment for a driver and the task of identifying the adaptive equipment most suited to an individual's needs may be made by:

    Of the 101 dealers who responded to the Louisiana Tech survey, it was the dealers themselves who made 37 percent of the decisions, compared with 30 percent for evaluators and 33 percent for consumers.

    In terms of training to use the special equipment installed for a driver, 54 percent of training was provided by the vehicle dealer and 32 percent by a certified instructor. According to the 101 dealers, about 15 percent of drivers received no training at all.

    More Information

    This report was prepared by Amanda Cowen, a summer fellow from the Joint Program in Survey Methodology sponsored by the University of Maryland and University of Michigan. She was assisted by Sharon Durant from the Bureau of Transportation Statistics. Questions may be directed to Ms. Durant at (202) 366-6049.

    1   U.S. Department of Transportation, Bureau of Transportation Statistics, Omnibus Household Survey, June 2002.

    2   The potential data bias introduced by an overall response rate of about five percent means that the data contained in this Note should not be used to draw national conclusions. Instead, they are best considered as information from the 101 dealers only.