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Letter to the Editor: Update on Experiences of a Driver with Vision Impairment
when Using a Tesla Car—Full Self-driving (Beta) in City Driving
In this letter, we provide an update to our clinical report titled
“Experiences of a Driver with Vision Impairment when Using a
Tesla Car.”
1
Our original report documented the experiences of a
patient with Stargardt disease (20/182 binocular visual acuity)
when using assisted and semiautonomous driving systems in a
Tesla Model Y car to support his daily driving (Tesla Inc., Austin,
TX). The report addressed the patient's driving habits, difficulties
encountered while driving, adaptive strategies used, and his use
of different driving features in the Tesla car between September
2020 and October 2021. In addition, the report detailed how the
patient integrated use of a bioptic telescope (6Ocutech monoc-
ular for the left eye) withuse of the Teslacar system(s): specifically,
how he used the bioptic to obtain a magnified view of the road sit-
uation before granting permission to the Tesla car system(s) to per-
form a maneuver.
Previously, the patient reported major difficulties while driving in
urban areas, particularly when navigating complex intersections and
making unprotected left turns. Therefore, an automated driving sys-
tem that could assist with city driving was at the top of his wish list
for technology support. In October 2020, Tesla initially released a
beta version of its Full Self-driving (FSD) software to a small group
of users in the United States,
2
and in October 2021, the system en-
tered wider availability to more users. The new system introduces an
Autosteer on City Streets function that can automatically make turns
and navigate within cities (Table 1). However, users must participate
in a Safety Score Program and meet certain safety and monitoring re-
quirements to be qualified to use the FSD Beta system.
After learning that the patient had enrolled in Tesla's FSD Beta
program, we conducted an initial interview with him at Envision Re-
search Institute in July 2022. We then followed up with a second
interview via telephone in October 2022 to record his experiences
after using the FSD Beta system and to summarize hisoverall expe-
riences after using a Tesla car for 2 years. In each interview (30 mi-
nutes to 1 hour), the first author (JX) used a predetermined set of
open-ended and closed-ended questions to guide the conversation.
Follow-upquestions were used, when needed,to explore certain re-
sponses in more depth for a fuller understanding of the patient's ex-
periences. When preparing thisletter, the first author contactedthe
patient to further clarify and verify information. Table 1 summa-
rizes the Autopilot and FSD features in the patient's Tesla car.
Tesla FSD Beta Use Experience in City Driving
The patient opted in to the Tesla Safety Score Program in June
2022. The program tracks the driver's driving safety performance
and provides a safety score based on five categories of driving per-
formance: forward collision warnings per 1000 miles, hard brak-
ing, aggressive turning, unsafe following, and forced autopilot dis-
engagement (Tesla Inc.). After being tracked for approximately
1 week, the patient received a score of 93 and successfully en-
rolled to be an FSD Beta system user (requiring a score of 90 or
higher). Among the five categories, the patient reported that he lost
most points in “hard braking”(deceleration: decrease in the vehi-
cle's speed greater than 6.7 mph in 1 second). This means that
the driver applied excessive force to brake the car when Autopilot
was not engaged. One possible explanation may be that the driver
may have been late to see things because of impaired vision and
had to brake harshly.
The patient reported that the FSD Beta system (from here on-
ward, specifically refers to the Autosteer on City Streets) could au-
tomatically change lanes and overtake slow cars, which he would
not do himself when driving manually in the city. Therefore, he trav-
eled in the left lane more often when using the FSD Beta as com-
pared with manual driving when he usually stayed in the rightmost
lane at the speed limit. Making left turns at intersections has been
often reported as a challenging situation by drivers with reduced vi-
sion. The patient reported using a new strategy when making left
turns at different types of intersections after having the FSD Beta
system: (1) for intersections with protected left turns (left turn ar-
row light), he lets the FSD Beta system drive; (2) at intersections
with stop signs, he will let the FSD Beta drive, and he will monitor
and correct the maneuver (take over the control and return to man-
ual driving) when he feels it is necessary; and (3) at four-way
nonsignalized intersections (no traffic lights or stop/yield signs),
he drives manually. After using the FSD Beta system for approxi-
mately 6 months, the patient reported less avoidance of left turns,
intersections, and city driving in general than was the case before
the FSD Beta system was installed. The patient also reported that
he felt more comfortable driving to unfamiliar cities again. How-
ever, the patient mentioned that the system could make him ner-
vous when making turns at intersections because it sometimes hes-
itates too much and makes the steering wheel jerk.
The patient used both the FSD Beta and the Navigate on Autopi-
lot systems on his car. However, he found that the switch between
the two systems could be confusing because the mode of operation
differs. The FSD Beta system (designed for use in urban environ-
ments) operates automatically without requiring the driver's permis-
sion, performing all necessary maneuvers (Table 1). In contrast,
Navigate on Autopilot (used on highways) still requires the driver's
engagement to grant permission to make a maneuver (Table 1). Spe-
cifically, the driver must push a control stalk under the steering
wheel or tap the accelerator to permit the car to make the maneuver.
Bioptic Telescope Use when Driving with FSD
Beta System
In city driving, before having the FSD Beta system, the patient
reported using his bioptic telescope mainly for monitoring traffic
signs or light changes before allowing the car to start driving
through an intersection (using Traffic-Aware Cruise Control and
Traffic Light and Stop Sign Control [Beta]).
1
After using the FSD
Beta on city streets, he estimated a 10% decrease in use of his
bioptic telescope because the FSD system does not require his con-
firmation and permission to execute maneuvers.
CORRESPONDENCE
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Accessibility Challenges because of
Vision Impairments
In addition to the Tesla car user interface accessibility chal-
lenges we previously reported, the patient noted a few more situa-
tions where visual challenges with using the Tesla information in-
terface could potentially cause safety concerns.
1
When the FSD
Beta makes a left turn automatically, the car will first move to the
right a bit to create more space for the left turn, and a left turn arrow
will appear on the central information touchscreen. However, this
rightward movement can be stressful for the patient because he
cannot see the left turn arrow on the screen display and there is
no auditory confirmation that the car is preparing to take a left turn.
Therefore, he commented that it would be helpful if the blinker in-
dicator on the touchscreen could be larger or the system could pro-
vide an audio reminder.
In a Tesla car, navigation update and car performance warning
notifications normally appear on the center screen. These notifica-
tions usually appear briefly in a text bubble, which is difficult for
drivers with visual impairment to see, especially when driving.
The patient reported that he normally only checks these notifica-
tions with his phone magnifier after he arrives at the destination
when the car is parked. However, this delayed awareness of the
warning notifications can cause safety concerns. The patient pro-
vided an example: during an interstate road trip, a very low tire
pressure warning appeared at the bottom of the screen. He was
only aware of this notification after he arrived at his destination.
He said that he would not have continued driving on the tire if he
had seen the notice sooner.
A 2-year Tesla Car Experience Summary
After owning a Tesla car for 2 years (October 2020 to October
2022), he drove a total of 30,000 miles with six cross-state
long-distance journeys; no accidents or near misses were reported.
In October 2022, he reported that he drove manually for approxi-
mately only 5% of the time in certain situations: (1) rush hour traf-
fic in residential areas and neighborhoods (more traffic in rush
hour, many parked cars on streets, less clear lane markings on res-
idential roads), (2) parking and navigating around parking lots, and
(3) situations when the car system disengaged (e.g., poorly marked
road) or when he did not feel comfortable. He stopped avoiding
night driving, long-distance travel, and driving to unfamiliar cities
and also decreased avoidance of left turns, intersections, and city
driving in general. However, he did report that he still avoided driv-
ing in snow or bad weather.
He reported a similar level of mental and physical workload
when driving with Autopilot or the FSD Beta system as he experi-
enced in manual driving. Because of full awareness of his vision
condition, he still put 100% attention on driving and supervising
the car automation systems. The only situation that he may pay less
attention to is when using Navigate on Autopilot for interstate high-
way driving. However, once he notices any orange signage (e.g., traffic
cones), he will be on high alert because he is aware that he is ap-
proaching a construction area or some type of disruption of regular
travel. Overall, his awareness of the road environment has increased
and the stress from driving with impaired vision has greatly decreased
when driving with Tesla-assisted and automated driving systems.
DISCUSSION
Using the Tesla Car Autopilot and FSD (Beta) systems greatly
improved the patient's confidence with driving and allowed him
to comfortably drive in many more situations than he used to. He
reported fewer self-imposed driving restrictions and less stress
when driving, and he felt much more comfortable and confident
when driving long distances, in the city and at night. The patient
in this study, like normally sighted drivers who used partially and
conditionally automated driving systems in prior studies,
3–5
re-
ported an increased frequency of long-distance trips after using
Tesla Autopilot and changes in route choice after using the FSD
Beta system. Drivers, in general, are more willing to engage in
TABLE 1. Autopilot and FSD features in patient's Tesla Model Y*
Features Description
Autopilot Traffic-aware Cruise
Control
Matches the speed of the driver's car to that of the surrounding traffic
Autosteer Assists in steering within a clearly marked lane and uses traffic-aware cruise control; measures the amount
of torque that the driver applies to the steering wheel, and if insufficient torque is applied, an escalating
series of audible and visual alerts reminds the driver to place hands on the wheel
Enhanced
Autopilot
Navigate on Autopilot Actively guides the car from a highway's on-ramp to off-ramp, including suggesting lane changes,
navigating interchanges, automatically engaging the turn signal, and taking the correct exit
Auto Lane Change Assists in moving to an adjacent lane on the highway when Autosteer is engaged
Autopark Helps automatically parallel or perpendicular park the car
Summon Moves the car in and out of a tight space using the mobile app or key
Smart Summon Navigates more complex environments and parking spaces, maneuvering around objects as necessary to find
a parking lot
FSD
Capability†
Traffic and Stop Sign
Control (Beta)
Identifies stop signs and traffic lights and automatically slows the car to a stop on approach to a red light or
stop sign, with the active supervision of the driver
Autosteer on City Streets
(Beta)
Navigates around complex urban environments automatically, including making turns, changing lanes,
passing cars, and navigating the vehicle through intersections, among others
*This information anddescriptions were mainly drawn andadapted from the Tesla Web site (www.tesla.com). †FSD Beta can be summarized as a host of
new features that are not yet debugged. FSD = Full Self-driving.
Correspondence
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leisure driving activities and fulfill unmet travel needs owing to the
ease of travel provided by the automated system and to gain expe-
rience and explore the system's usefulness.
3,5
Furthermore, drivers
with vision impairments can now drive in situations previously inac-
cessible to them, leading to increased driving exposure alongside
normally sighted drivers. However, extended travel time in more di-
verse driving situations with the system may lead to new safety risks
for drivers with vision impairments. This is particularly true when
drivers exceed their mental and physical capacities to safely per-
form the driving task, such as effectively monitoring automation
systems, responding to road events and hazards, and responding
to takeover requests.
In comparison to manual driving, normally sighted drivers reported
a decrease in both mental and physical workload and stress when
using Autopilot because of its ability to take over the lateral and longi-
tudinal aspects (i.e., steering and acceleration/deceleration) of driving
tasks on highways. However, when using the FSD Beta, they reported
an increase in workload and stress,
3
as the current system requires
constant supervision and preparation for intervention in case of unsafe
system behavior (this stress may be mitigated in the future as the sys-
tem achieves better performance and requires less driver supervision).
However, this patient reported a similar level of mental and physical
workload, but a decrease in stress when using both the Autopilot
and the FSD Beta system. Autopilot and the FSD Beta system can
share some driving responsibilities, but this patient still needs to pay
full attention (use the same mental and physical workload) to monitor
the road, interact with bioptic telescope, and engage with car systems
to either grant permission to Autopilot system or take corrective ac-
tions with FSD Beta engaged. However, compared with manual driv-
ing, driving with these systems still greatly decreased his stress when
driving with vision impairment. The patient commented, “Having
these systems is like having a second pair of eyes. The car definitely
added an extra layer of safety in addition to my own vision.”
It is important to note that the FSD Beta system is currently in a
beta testing phase and still in development, and many users have
reported usage problems and potential safety concerns.
3,6
As
automation technology continues to advance, it is possible that
some of the issues and use challenges identified by this patient
and other users may be remedied in future versions of the Tesla
FSD system or in other semiautonomous vehicles. Our main goal in
reporting this patient's entire experience across 2 years is to demon-
strate the possibilities of using a car with level 2 automation to sup-
port driving safety and mobility opportunities for drivers with vision
impairment. We also want to emphasize the importance of manual
driving skills and the need for full engagement when driving with
any semiautonomous system. As we can see, the driver still needs
to manually navigate through situations that he reported having the
most difficulty with, such as making left turns at uncontrolled inter-
sections. Drivers need to be aware of the limitations of existing tech-
nologies and still make use of their own safe driving practices and
adaptive strategies in these situations. The potential problems and
challenges this patient encountered are likely to occur with other
drivers with visual challenges when using Tesla cars or other assisted
and semiautonomous driving systems. These insights may be helpful
to the automotive industry as meaningful guidance for development
of future assistance and automated driving systems.
Jing Xu, PhD
Envision Research Institute
Wichita, Kansas
Schepens Eye Research Institute of Massachusetts Eye and Ear
Harvard Medical School
Boston, Massachusetts
xujingcau@gmail.com
Karen Kendrick, OTR/L, CLVT
Envision Vision Rehabilitation Center
Wichita, Kansas
Alex R. Bowers, MCOptom, PhD, FAAO
Schepens Eye Research Institute of Massachusetts Eye and Ear
Harvard Medical School
Boston, Massachusetts
REFERENCES
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Software Is Starting to Roll Out to Select Cus-
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2020/10/21/21527577/tesla-full-self-driving-
autopilot-beta-software-update. Acc essed Oc tober
21, 2020.
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Use of Standard Autopilot and Full Self-driving
(FSD) Beta: Results from Interviews with Users
of Tesla's FSD Beta. Front Psychol 2023;14:
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4. Hardman S, Chakraborty D, Tal G. Estimating
the Travel Demand Impacts of Semi Automated
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Multimodal Technol 2022;6:86.
Correspondence
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