James R. Marston, UCSB Geography Department
Email: <marstonj@geog.ucsb.edu>


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® 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 traveler.

Research Problem

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 traveler.

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 research

Experimental Design

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® 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.

Major Hypotheses

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:

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® 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 ticketing tasks.

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 machine.

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.

Field Test

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.

Main Results


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 & Tested Objectives

Objective 1

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.

Objective 2

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 that of the general public.

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.

Objective 3

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.

Objective 4

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.

Objective 5

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.

Objective 6

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 documented before.

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 attention.

Objective 7

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 access.

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.

Further Reading & Resources

  1. coming soon: James Marston's white paper: The Accessible City
  2. Email the author, James Marston: <marstonj@geog.ucsb.edu>

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