2001 Conference Proceedings
Go to previous article
Go to next article
Return to 2001 Table of Contents
EMPIRICAL MEASUREMENT OF BARRIERS TO PUBLIC TRANSIT FOR THE
VISION-IMPAIRED AND THE USE OF REMOTE INFRARED AUDITORY SIGNAGE
James R Marston, UCSB Geography Department
For the first time in the history of humanity a technological
device is finally available to give vision-impaired people access
to spatial and environmental cues. As the installation of these
devices grows, many questions need to be answered to ensure that
limited resources are spent wisely and efficiently. The impacts
of Remote Infrared Audible Signage (RIAS) will affect all aspects
of travel and access to urban opportunities. This research helps
answer the most relevant questions needed to understand the
benefits of this new technology and if it can finally give blind
travelers equal access to transit and public buildings, as
required by the ADA.
It is "common knowledge" that people with vision impairments
face obstacles to independent travel and probably take longer to
make trips and also make fewer trips. What is not well understood
is which of the many tasks of transit present the biggest
barriers to travel. Without this knowledge planners and agencies
are "blind" to how best improve access for this population. It is
also not understood how much of the unemployment problem of this
group is affected by transportation barriers. This research will
also reveal the financial benefits this group estimates these
changes in access would be worth to them.
It is time to finally bring to light the "penalties" of time and
effort that prevent freedom of independent travel for this
population. In-depth analysis of these barriers to transit access
will help channel the energies of many advocacy and governmental
agencies in trying to finally solve the problem of equal access
for the blind and vision impaired. It will provide much needed
data for the implementation of the spirit of the ADA, in ensuring
equal access to this group.
RIAS technology works something like the infrared remote control
device used for channel selection on television sets. An infrared
beam to a hand-held receiver that speaks the message to the user
transmits the speech imbedded in the sign. It must be emphasized
here that unlike "chirping" and other auditory traffic signals,
which use mounted speakers, there is NO environmental noise
pollution with this system. Unlike auditory traffic signals which
merely provide an auditory signal of a certain duration during
which time it is "safe" to cross a street, Talking Signs(R) go
well beyond the concept of a simple indicator. They are in effect
an information system. The Remote Infrared Audible Signage
equivalent of an auditory traffic signal transmits the names of
the cross streets (which must be heard through the user's
receiver), the address number of the block, and the direction the
receiver (person) is facing. It gives a distinct WALK or WAIT
signal for traffic in the direction the traveler is facing, as
well as a beam that defines the width of a safe passage corridor
for crossing a street.
Any location that is commonly identified with a written sign can
be identified with an auditory sign. These devices have the
potential to give blind and vision impaired people access to the
information that the sighted take for granted. They can travel
independently, shop, visit buildings such as government offices,
transit centers and rail platforms, libraries, malls, hotels, and
other large spaces that are so confusing to the blind
The use of RIAS is rapidly expanding around the world and new ADA
guidelines will mention them as appropriate for Accessible
Pedestrian Signals. We must gain a better understanding of the
proper situations and locations for their placement. Little is
known about all the factors and difficulties that restrict travel
and independence for the vision impaired person. Sighted people
are usually amazed at how the blind can cross a busy street,
often watching in awe as this task is done. However, our research
has shown that many other tasks present more functional barriers
to travel than street crossings. For example, the "simple" task
of finding and identifying a bus stop in an unfamiliar area is
ranked much more difficult than crossing a street by a blind
We tested 30 blind subjects in and around the CalTrain station
in San Francisco. We have collected many data on activity
patterns, frequencies and travel times. We also have data on what
types of trips are avoided because of transportation and vision
problems. We have data on the perceived value of accessible
transit and monetary benefits to be gained by better access. Data
were collected on the difficulties caused by making transfers and
how they restrict independent travel. These data can increase our
knowledge about travel without sight and where to put our
resources to ensure equal access for the blind. Society at large
will also benefit as more people in this group can join the
economic base of the city.
This research has two main concerns. We study in-depth the
specific problems and difficulty of various transit tasks and how
independence and travel is affected by these problems. We also
determine if auditory signage can relieve those difficulties and
increase mobility and activities. Because each subject did the
same tasks both with and without the auditory signs, we are able
to see what significance the absence or presence of direction and
location identification has on the blind users. In this way,
subjects act as their own control, giving greater power to the
Site Selection Rationale
After several years of testing auditory signage in controlled
and small environments, it was highly desirable to test the
system in a much larger urban transit environment with "real
world" simulations and tasks. We chose the robust environment
that was available at the San Francisco CalTrain station. It gave
us the ability to test subjects transferring between 4 different
transit modes in an area that had about 50 Talking Signs(R)
transmitters. This rich environment was a superb place to conduct
much needed research and we designed a very broad range of
questions and tasks to take full advantage of the opportunity. It
is quite difficult to get a group of blind travelers together for
testing at a site and can also be quite expensive and
time-consuming. For this reason, once we planned the experiment,
we filled it with as many relevant tasks and questions as could
be fit into a schedule without causing subject fatigue.
There is no doubt that vision impairment detracts from
independent travel restricting safe and efficient travel. Trips
take much longer, especially in unfamiliar areas and therefore,
the number of activities undertaken are much less than the
general public. The dismal unemployment rates of this group
confirm their lack of mobility. In fact, there is talk of
"lowered expectations" that many vision impaired people exhibit.
Much attention has been paid to reducing the structural barriers
that face those with mobility restriction but to date, little
attention has been paid to the functional barriers that restrict
equal access to urban opportunities and travel for the vision
impaired traveler. Lack of spatial information normally acquired
through vision is the barrier that restricts access for many
blind travelers. We hypothesize:
- That the addition of auditory and directional cues, delivered
through Remote Infrared Auditory Signage will increase perception
of travel safety, efficiency and independence.
- That walking and searching times between locations will be
reduced when the system is used.
- That blind subjects will report a perception that they will
travel more often and to more places.
- That blind subjects will report they will be more willing to
use public transit instead of relying on others or expensive
modes such as paratransit or cabs.
- That subjects will rate a variety of transit tasks as much
less difficult if RIAS is installed
- That blind subjects will report a wide range of areas and
situations where RIAS adds much to their safe and independent
Outline of Tasks
Transfers and mode changes can be difficult barriers for many
vision impaired and other print handicapped individuals. Our
research hypothesis is that these people will be able to use
Talking Signs(R) to safely and easily move from one form of
transit to another, crossing streets and tracks with much less
anxiety and time then when attempting these mode changes without
any assistive devices.
Pre-test interviews gave us information on the subjects'
blindness characteristics, travel and activity behavior, and
perceived difficulties while using transit and making transfers.
These same questions were asked after the experiment with RIAS to
determine if changes had occurred. We tested 30 blind and vision
impaired people navigating a course in San Francisco in and
around the CalTrain station at 4th, Townsend, and King Streets.
Subjects attempted to walk and make 5 different mode transfers,
making realistic stops along the way for various amenities and
We tested subjects making 5 transfers. The first transfer task
(Task 1, CalTrain to MUNI Light Rail) started at a gate at the
CalTrain station as if they had just disembarked from the
commuter train. They exited the station and crossed a street
intersection equipped with RIAS that gave intersection
information and also guided them across the crosswalk where they
found RIAS directing them to the MUNI Light Rail station fare
The next task (Task 2, MUNI to CalTrain) took them from the
street corner near the MUNI fare machine back to the CalTrain
station where they found another gate for boarding the train.
Next they were taken to a nearby cab stand from where they
attempted a transfer (Task 3, Cab stand to CalTrain) back to the
station and found another gate door for boarding.
For the next task (Task 4, CalTrain to Bus Shelter), they exited
the station and went to the corner, crossed the street, and found
where a specific bus shelter was located. From the bus shelter
they walked back to the CalTrain station (Task 5, Bus Shelter to
CalTrain), where they found yet another gate entrance for
boarding the commuter train. Altogether, subjects traveled 5
different routes to simulate making five transfers using 4
different forms of transportation.
We recorded travel time, errors, and requests for assistance
during the experimental trials. In-depth exit interviews were
conducted to measure attitudes and feelings about this
technology. We asked about difficulties of various transit tasks,
had subjects rate the benefits of the technology, and collected
data about their spatial understanding of the environment.
Subjects compared their regular method of travel to their
experience using the RIAS, specifically rating street crossings,
in-terminal searching and walking tasks, and making transfers in
general. We established if subjects felt that RIAS gave them
freedom and independence so they could travel without using
expensive paratransit services. The interviews gave us further
insight into how the auditory signs help them better understand
the environment and increase their mobility.
At the end of the post-test interview, a debriefing
questionnaire was used to evaluate how helpful RIAS was in
various locations, if they should be installed there, and other
consumer evaluations of the system. Other questions asked about
their perceived trip-making behavior and difficulties of travel
in environments as fully served by RIAS as the test environment.
In this way we evaluated if the technology improved their ability
to use transit, their frequency of using it, and whether it
improved their quality of life by encouraging them to take trips
that they had previously not taken.
Although we have talked mostly about the blind and vision
impaired, this technology has much wider appeal. Other print
handicapped people like dyslexics, developmentally disabled,
illiterate, children, and people who do not read the local
language but can understand some speech can also benefit.
A combination of experimental methods and techniques are used in
this research. Pre and post-test interviews are given to all 30
subjects. Many of the questions are the same in both conditions.
They consist of a combination of 5-point rating scales on various
perceptions, we collect numerical data on the number of trips
they make on various modes and also the number of trips for
various activities and subject's walking and riding times for
these activities. Other data are collected by giving a choice of
possible answers or they can choose "other" and we fill in their
answer. Data on residential choice behavior, pre-planning for
trips to new locations and evaluations of the perceived
difference between their regular method of travel and the RIAS
system in regards to street intersections, in-terminal use and
making transfers are collected using non-timed open-ended
questions. This combination of question types helps establish
convergent validity and reduces experimenter bias in the phrasing
of questions and responses.
Since many of the same questions are asked before and after the
experiment, we collect data on within subject variation of the
impact of the system and also collect data on between subject
variations. The within subject data helps us to understand
differences for each individual, no matter their degree of
blindness, skills, SES or other variables. With within subject
data, more power can be gained with fewer subjects because one is
sure that, except for condition, the other variables are
identical. Between subject data allows for testing the
differences between a wide range of subjects.
We wanted to collect the most naturalistic and "real-life" data
possible so we conducted an experiment at the terminal test site.
Subjects were free to ask others for verbal assistance if needed
and use whatever techniques were best for them. We did not
manipulate any variables, although we did put a time limit of 4
minutes on each sub-task, in order to avoid undue stress and
extreme frustration. We gave them precise instructions to follow
for each walking task as far as path or locations to visit, and
when to start and stop.
We manipulate the order of the two conditions. Some used the
RIAS first and others used it after using their regular method.
Learning effects must always be considered when doing the same
task twice. It is normal for people to have some learning gain on
a second trial. Previous research has shown that people that use
the RIAS for their first trial had times and error production
quite similar to those who had walked the route first with their
own techniques and then tried the RIAS, especially in more
complex routes. Since many of the destinations have no readily
accessible cues to indicate "you are here," it is difficult to
"learn" a route after only one trial, especially for those with
no usable vision. In order to determine if this is the case in
this environment, we checked for the learning effect during the
first two trials.
We tested 15 subjects in one condition that we can compare both
within and between subjects. We also have another 15 subjects
that we can compare between subjects with their RIAS counterparts
from the first condition. We can also compare between subjects
those 15 that used their regular method first and those 15
different subjects who used RIAS first. With both between and
within subject experiment design in both conditions, powerful
analysis is insured.
- Many transit tasks are rated as difficult or very difficult
by blind travelers. After using the RIAS, these same tasks were
rated close to or at the rating of "not at all difficult."
- Subjects using RIAS had highly significant improvements in
- Subjects had to ask for help often to find their destinations
when using their regular techniques, but when using RIAS, no one
asked for help.
- Street crossings were much quicker and made more safely when
using RIAS.With the normal techniques, many subjects tried to
make unsafe street crossings and a few would not even attempt the
- Subjects using RIAS could travel independently and obtain
specific confirmation of their location and their arrival at the
- The use of RIAS greatly increased the acquisition of spatial
knowledge about the local environment and allowed people to
discover locations they were not even searching for.
- Blind users said that the use of RIAS would increase their
use of transit and allow them to make more trips.
- Subjects strongly agreed that RIAS should be installed at
many transit locations, including terminals, buses and rail cars,
at bus and transit stops, and at street corners.
Robust and significant results were obtained when we compared the
two conditions of the experiment. It is imperative that we gain a
better understanding of which locations create the most
difficulty for the blind and how RIAS can affect those barriers,
before committing large sums of money to these systems. There
remain 2 major themes that are investigated in this research.
First, we examine the differences between subjects with different
levels of blindness to establish parameters for those with total
vision loss, those with some light or shape vision and those with
some object vision. To date, little is understood about which
types of locations or objects create barriers to spatial
knowledge for various degrees of blindness. These results add
immensely to the knowledge about how to minimize these barriers
to independent travel for all types of blind travelers. The
second type of analysis looks at subject's reported perceptions
of various transit tasks and travel activity behavior
A review of seven specific and tested objectives concluded
Hypothesis: When using RIAS, walk and search times and requests
for assistance and error production will vary both as a degree of
blindness and the different types of location searched for.
People born blind have different travel skills than those who
are recently vision impaired. Little is know about what types of
objects allow for using these different skills. By using t-tests
or ANOVA we can obtain insight into how the degree of blindness
affects travel behavior and also to what extent RIAS would
improve that behavior.
Hypothesis: The vision impaired stay on a known transit route
longer than their sighted counterparts. Uncertainty about spatial
information is so strong that they do not make transfers as
readily as the general public. RIAS will give those people much
more information and make their behavior much more like the
We asked subjects both before and after the experiment about
their tendency to make transfers if they could save time.
Subjects estimated how much time they would want to save from a
60-minute transit trip before they would get off and make a
transfer to a faster mode. This scenario was repeated 6 times
with various walking distances and degrees of familiarity with
the area. These data were also collected from 30 sighted people.
These data are used to determine an exact impedance number for
distance decay and also for the degree of familiarity. We analyze
the difference between both conditions, between fully and
partially blind and against the sighted baseline population. This
novel data collection and analysis will allow transit planners to
more accurately address restrictions placed on the vision
impaired in an urban transit system. It will also reveal if RIAS
can eliminate the difference in behavior between the general
public and those with loss of vision.
Hypothesis: After using RIAS, participants will report a
perception of many more trips they would make if the system were
installed. Vision impaired people have a restricted activity
space and make fewer trips than the general public. They will
report activities that they do not undertake because of
transportation problems relating to their vision loss. They will
reveal a large pent-up demand for activities and trip making that
is not now being met.
Data on current trip making frequencies, the number of trips
they feel they do not make because of the lack of vision and the
number of trips they would make with more auditory geographical
information are analyzed both between and within subjects. This
helps determine how accessibility is affected by vision loss and
if additional auditory cues can change the level of
accessibility. This analysis determines if equal access is yet
part of the daily life of this group. The data show that people
do not make the trips that they desire, and reveal that
subsidized fares and other transit efforts to date are enough to
make transportation accessible.
Hypothesis: After using RIAS, participants will report that they
can make the same trip independently, without relying on others,
or using expensive means of travel. Current transit accessibility
is limited, and this group will report that in many cases they
cannot make a trip independently.
Subjects were asked both before and after the experiment to
consider 2 hypothetical transit trips of ten miles, on an
unfamiliar transit line with a transfer required. One scenario
was for a one time desired event, a concert, and the other was
for a daily job trip. Comparisons of the two conditions show that
RIAS adds immensely to independent travel.
Hypothesis: After using RIAS, participants will report trips as
being much easier. Subjects will report that many transit tasks
are very difficult. Degree of blindness and use of dogs will
affect their ratings for task difficulty.
We asked 26 questions about the perceived difficulty of
different transit tasks. The research showed that on a five-point
scale perceived difficulty was about two scale points better.
Analyses of the data after using RIAS reveal which tasks can be
made easier and allow transit planners to know specific locations
that need mitigation. To date, these robust data about specific
tasks are not available and hence effort is not always expended
on the correct solution to access problems.
Hypothesis: Participants will report specific problems that will
lead to new areas of investigation and will provide strong
confirmation of their desire for auditory signage to resolve
their access problems. The extended use of RIAS in this
experiment will give blind subjects new insights into the
problems they face as blind transit users that have never been
Input from blind people about access problem suffer from 2 major
problems; many congenitally blind people do not truly understand
what the world is like for the sighted and they also are
reluctant to voice their dependence on others. The use of RIAS
gives many blind people, for the first time, an idea of what the
sighted public takes for granted. The addition of direction and
identity cues make it possible for this group to navigate new
environments efficiently and safely the first time they attempt
it, with no help from others. This knowledge then sheds much
light on what the problems have been in the past once they have
gained this broader and more independent access to spatial cues
and the environment.
Evaluation of subjects responses to five open-ended questions,
dealing with differences between their regular methods and using
RIAS in regards to transfers, terminal navigation, street
crossings, trip making ability and their overall opinion of RIAS
are analyzed. For example, asking for help is so common for this
group that they usually don't mention it as a problem. We found
that after using RIAS they strongly mention they "don't have to
ask for help" as one of the major differences. This shows both
the improvements when using the system but also sheds light on
what travel is like without sight. By analyzing their responses
to these 5 questions, we identify specific barriers to
independent travel and also how RIAS can mitigate these factors.
Answers to questions about transfers or terminal use, for
example, help identify where planners should focus more
Hypothesis: Subjects will report that they could make more money
and spend much less on travel assistance if they had equal access
to transit. Transit access needs, for the vision-impaired are not
being met by transit providers. They will report they would be
willing to pay much more than the travel subsidy they receive if
barriers to transit were removed and they truly had equal
We collected much financial data from our subjects. In the
pre-test interview they told us how much more than could earn if
they had equal access, how much they spend on travel assistance
and how much they would be willing to pay to have equal access to
transit. After using RIAS, they answered those questions again.
Go to previous article
Go to next article
Return to 2001 Table of Contents
Return to Table of
Reprinted with author(s) permission. Author(s) retain copyright.