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Note: The following article originally appeared in the Winter 1997 issue of "Human
Connections", a newsletter for the alumni of the College of Health and Human
Services, Western Michigan University. It is republished here with permission.
Low
vision driver education training
by Charles P. Huss, Blind Rehabilitation,
'76
Introduction
Safe operation of a motor vehicle requires that the driver
be able to detect visual clues with his or her field of vision and be able
to distinguish them clearly enough to allow the brain to make an accurate
assessment as to the correct action required. Many individuals presenting
mild to moderate visual acuity loss are capable of picking up visual clues
with their field(s) of vision but, because of their reduced central visual
acuity or detail perception, are unable at times to define or interpret
these clues. Since 90-97 percent of all driving clues are picked up by
one's field of vision, researchers at the West Virginia Rehabilitation
Center (WVRC) hypothesized that certain visually challenged individuals,
with full fields of vision and mild to moderate central visual acuity
loss, could learn to drive safely with appropriate low vision aids and
specialized driver education training.
In 1985, a multidisciplinary group of researchers
consisting of a driver rehabilitation specialist, an optometrist
specializing in low vision practice, a psychologist, an orientation and
mobility specialist, an audiologist, and an occupational therapist set out
to explore and formulate ways of screening, training, and assessing the
driving potential of a select group of visually challenged individuals.
The results and conclusions of this ten-year effort will be discussed in
the following article.
Vision Requirements for Candidates Selected for
Inclusion in Study
Visually challenged students who were accepted for
participation in WVRC's initial three-year pilot study (1985-1988), and
identical low vision driver services which followed for the next seven
years (1989-1996), had to meet and maintain the following visual
requirements:
- distance visual acuity between 20/50 and 20/200 inclusive,
with best standard spectacle or contact lens correction in the better eye;
- visual field of 120 degrees horizontally and 80 degrees vertically or
greater in the same eye as used for the visual acuity determination;
- 20/40 or better distance visual acuity using distance optical low vision
aids prescribed by either a licensed optometrist or ophthalmologist;
- no
ocular diagnosis or prognosis which was likely to result in significant
deterioration below the protocol levels of visual acuity and visual fields
as stated above.
All candidates who volunteered to continue in this pilot
study/continuum of services were also required to submit to other
evaluations administered by the multidisciplinary team of professionals as
stated previously. Since driving is a complex task, researchers felt that
the results of the latter assessments would provide a clearer picture as
to the strengths as well as areas needing improvement for this group of
individuals who, for the most part, did not anticipate that one day they
might qualify for driver education services, much less access to driver
licensure.
Initial Screening Results
Of the 107 individuals identified by clinical low vision
sources as meeting this study's visual protocol, 69 individuals returned
voluntarily to participate and complete the series of evaluations
conducted by the multidisciplinary research team. Of those, 69, 56
individuals illustrated acceptable performance scores and were invited to
return to the Center at a later date to initiate formalized programs of
low vision driver education training.
Since most candidates never dreamed that someday they
would be given the opportunity to demonstrate their functional competency
behind the wheel of an automobile, evaluation results illustrated that
most students had problems related to the dynamics of the driving task
such as:
· Distance eye-lead time · Head and eye scanning ·
Following distance from other road users (big picture awareness) ·
Yielding procedures when turning or when approaching crossroads · Hazard
perception awareness · Independent decision making · Distance detail
awareness and identification.
Training Strategies
Forty-seven of those 56 participants who completed the
aforementioned multidisciplinary assessment procedures satisfactorily
returned voluntarily to initiate a comprehensive yet individualized 6 - 8
week low vision driver education training program. The latter consisted of
concurrent education experiences involving approximately 30 hours of
classroom driver education instruction, an additional 40 hours of vision
utilization training as a passenger in a vehicle (with and without the use
of low vision aids), and approximately 50 hours of actual on-road driving
under the auspices of a certified driver rehabilitation specialist. All
aspects of hazard perception and independent decision making were covered.
All on-road driving was undertaken in a dual brake controlled vehicle. In
addition, various audio and video self-study formats as well as remedial
driver education classroom instruction (evenings) were incorporated into
students' daily class schedules as needed or suggested by project
staff.
Two instructors, a driver rehabilitation specialist and an
orientation and mobility specialist (the latter serving primarily as a
visual skills instructor), shared and collaborated on teaching
responsibilities. For example, after driving a designated route,
respective students would then be taken by car as passengers over the same
route with their visual skills instructor to review and remediate any
problem areas which arose; yet could not be addressed at the time by the
driver rehabilitation specialist because of the dynamics of the driving
scene. Such on-site reviews might include: a review of roadway
characteristics, awareness of fixed as well as other hazards affecting
one's path of travel and/or speed, presence or absence of pavement
markings or road signs, and understanding of any traffic control devices
present.
Assessment Techniques
A third area of investigation by project researchers was
observing, evaluating and rating the dynamic driving behaviors of students
on a standardized 40-mile test route. The latter was developed by and
patterned after Michigan State University's Driver Performance Measurement
(DPM) research.
This weekly in-car assessment, instituted midway through
each student's respective training program, included the student driving
through rural, residential, business, and inter-city settings. It exposed
the student to a wide range of driving experiences - some easy, which most
drivers are expected to handle without difficulty - and others more
complex, which even the best drivers may have problems negotiating. Two
trained evaluators were always present with the student during respective
runs.
Such standardized procedures proved to be a very effective
method of establishing a baseline on and an ongoing assessment of progress
in driver performance of project candidates.
One major conclusion from repeated use of DPM procedures
with project candidates throughout this ten-year study was that
individuals who completed low vision driver education at WVRC
satisfactorily performed at a level comparable to their normally sighted
counterparts in terms of basic visual skills and demonstrated above
average skills in vehicle handling and ability to react to traffic
hazards. Another clear finding is the strong need for the continuation of
formalized low vision driver education programs like that existing at
WVRC, especially for visually challenged individuals who have not
adequately prepared themselves conceptually for the rigors involved in the
dynamics of the driving task.
Driver Licensure
Thirty-one individuals who completed WVRC's formalized
program of low vision driver education training satisfactorily were
afforded the opportunity to undergo comprehensive driver license testing
by specially trained driver license examiners employed by the West
Virginia Division of Public Safety. The latter testing included: vision
re-examination at the completion of training, road laws knowledge tests,
environmental awareness screening (functional vision assessment with and
without low vision aids while seated as a passenger in a vehicle), and an
actual on-road test (approximately eight to ten miles in length). The
latter was conducted in a dual brake controlled vehicle provided by
WVRC.
Eventually, all 31 of these individuals became legally
licensed to drive in West Virginia. Restrictions were applied on a
case-by-case basis by the West Virginia Division of Motor Vehicles and
included such driving restrictions as: daytime driving only, 50-mile
radius, use of BiOptics, or no interstate driving.
Conclusion
A telephone survey, conducted by this author during
October 1996, with each of the 31 participants who completed training
satisfactorily and are now licensed, revealed:
- An accumulation of 215.0 total person years of driving
for this group of visually challenged drivers
- Nearly 100 percent
educational and/or vocational placement
- A change in marital status for
12 graduates (single status to married status within five years after
licensure)
- Both accident-and violation-free driving records by 14 of 31
graduates
- At least one accident by 12 graduates (18 accidents for the
total group), yet they were not at fault in ten of those accident
situations
- At least one minor traffic violation (eight violations for
the total group) by seven graduates
- Involvement by only two drivers in
both accidents and violations
- Twice the number at-fault accidents and
traffic violations by those falling in the 20/50 to 20/70 visual acuity
category versus those graduates falling in the 20/80/ to 20/120 or 20/140
to20/200 visual acuity category.
Distance Visual Acuity Ranges
- 20/50 - 20/70 8 males 3 females
- 20/80 - 20/120 3 males 3
females
- 20/140 - 20/200 9 males 6 females
Since the onset of the West Virginia Study, the number of
states which now officially permit the issuance of restricted driver
licenses to visually challenged individuals utilizing BiOptic telescopic
lens systems has risen from 11 states to approximately 29 in 1997. 38
in 2002.
A legislative proposal is being submitted to the 1997 West
Virginia Legislature which is intended to: expand formalized low vision
driver education and training programs instate within the public as well
as the private sector; facilitate the screening, training, and testing
process for such applicants who wish to drive legally; and develop fair
standards which will ensure that public safety issues are addressed and
maintained.
WVRC is a public/residentially based vocational
rehabilitation facility. It is operated by the State of West Virginia's
Division of Rehabilitation Services.
Those interested in more information should write or
call:
Charles P. Huss, C.O.M.S. Coordinator, Low Vision Driver
Services
West Virginia Rehabilitation Center P.O. Box 1004 Barron Drive
Institute, WV 25112 TEL: 304-766-4803 FAX: 304-766-4816 Charles
P. Huss is an Academy Certified Orientation and Mobility
Specialist with 25 years of teaching experience with
visually impaired individuals [K-Geriatrics].
- As an adjunct, the Low Vision Centers of Indiana have produced a video titled
"BiOptic Driving", and two clips are available here.
If you do not have high speed internet access, these will take an hour+
to download. Each is in MPEG format that may be viewed with Microsoft
Windows Media Player.
Clip
1 7.21 Mb (Before behind-the-wheel training)
Clip
2 7.06 Mb (Sue Henderson CDRS - the training)
Produced
by: Low Vision Centers of
Indiana, the video is 9-10 minutes in VHS
Format. It gives a good introduction to BiOptic driving and may help
with professionals, patients, family, legislators, etc.
Richard
L. Windsor, O.D., F.A.A.O.
Craig
Allen Ford, O.D., F.A.A.O.
Todd
J. Fettig, O.D.
Laura
K. Windsor, O.D.
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