1994 VR Conference Proceedings

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Access to Two-Dimensional Information

By: James R. Fruchterman
President, Arkenstone


People who have a significant visual impairment face two primary challenges from their disability: access to information and personal orientation and mobility. The objective of adaptive technology developed for blind people is to provide tools that address these needs. Over the past decade, computers and reading machines have greatly improved access to information, by providing access to electronic information and the majority of print information. However, access to maps and other two-dimensional graphical information has remained a problem. Much work has concentrated on offering tactile access to this information, with limited success.

There is a new system that takes a completely different approach to this problem by using text-based virtual reality techniques. Atlas Speaks, a "talking map," has been jointly developed by two nonprofit organizations specializing in the adaptive technology field: Arkenstone of California and Visuaide 2000 of Quebec, Canada. This new approach offers many advantages and truly delivers the major breakthrough in access to maps. The techniques used are general enough to be used in accessing two-dimensional information of many different types and even three-dimensional information. Combining this access to map information with personal orientation is a further new system, Strider, a "walking talking map." Strider uses position information from the Global Positioning System to locate the user in relation to the map database being used.

I will describe how Atlas Speaks works, a method of sharing geographical information, as well as other implications of the system. How Atlas Speaks differs with and complements other approaches to graphical access will also be covered. Short term and long term plans for the system will be projected, including availability information for the U.S., Canada and other countries.

How It Works

Atlas Speaks is a PC application that uses a Geographic Information System ("GIS") electronic map database. These map databases have been developed commercially for automotive use, at great expense by ETAK, Inc. By carefully digitizing maps from government surveys, ETAK can link highly accurate latitude and longitude information with map features, such as streets, addresses and major landmarks. This linkage works both ways: you can ask where a certain intersection is and be told its precise location, or, you can give a precise location and find the nearest street or address.

Atlas Speaks makes these highly detailed map databases accessible. The information in the databases is essentially text, latitude and longitude information linked with street names, intersections and addresses. One way to think about a GIS database is as two-dimensional information laced with text labels. Using standard access devices such as voice synthesizers or braille displays, Atlas Speaks outputs these text labels in a form blind people can use.

Pick a square area and specify its location and dimension on the earth (hopefully an area where we have a database!). Atlas Speaks will draw on the PC screen the features within the square that are the most important. For most urban areas, this will be a grid of streets. This visual map can be enlarged for low vision people, or can be printed out as a tactile image. By pointing to any spot in that square, you should hear the geographic information that corresponds with that point, or the geographic feature closest to that point.

There are a wide variety of ways to interact with this information. Rather than enumerating them now, we will take a virtual tour of the neighborhood of Arkenstone's offices and explore both the area and the method of exploration!

Exploring Virtual Sunnyvale

Our existing prototype of Atlas Speaks needs to know the region you want to explore. The United States is divided into approximately three hundred regional maps, where over 99.5% of the population of the U.S. resides. The San Francisco regional map covers an area over 100 miles long and approximately 40 miles wide. Since Arkenstone is located forty miles south of San Francisco, our offices are located in the San Francisco region.

For simplicity of explanation, we will describe three different types of controls for our virtual exploration. First, we have menus for specifying a wide array of setup parameters. Second, there are hot keys for asking for specific information such as "Where Am I?" which gives the nearest address or the nearest intersection. Third, the direction keys move us about. The up arrow moves us in our current direction of travel, the left and right arrows rotate the direction we are facing.

We start our exploration by choosing a starting point. Using the menus, we type in "1390 Borregas Avenue," Arkenstone's address. Checking the database, Atlas Speaks finds only one instance of that address in the San Francisco region, the correct one in Sunnyvale. If we had typed in a common address, such as 1001 California, the database would present eight locations in the region with that address unless we specified the city when we entered the address. When we confirm that the address is 1390 Borregas Avenue, Sunnyvale, Atlas Speaks then draws a map centered around this address, with a marker showing our current address. The dimensions of the map are approximately one mile square, which is the smallest and most detailed scale available.

Using different keys, we begin asking questions about our locale. The Where Am I? key answers "1390 Borregas Avenue." The closest intersection key answers "4 way intersection 176 feet to the north, Caribbean Drive and Borregas Avenue." The right key says "facing south on Borregas." If we press it again, it says "facing north on Borregas." This tells us that we are in the middle of a street. Our standard exploration mode constrains travel to the streets in the database and the basic movement unit is proceed to the next intersection in the direction we are travelling. We also can control the amount of information we receive about the area we are exploring. For now, let's focus on directions and street names, but ignore address numbers. For simplicity, we will list the commands and the information we receive as we walk around a large block.

Right: "facing south on Borregas"

Forward: "4 way intersection with Caspian Court and Caspian Drive." (the cross street has different names on the left and right)

Forward: "4 way intersection with Java"

Right: "Facing west on Java" (we've turned from going south on Borregas to going west on Java)

Forward: "Bordeaux Drive"

Forward: "4 way intersection with Mathilda, facing west on 3rd Avenue" (Java has changed its name to 3rd at this intersection)

Right: "Facing north on Mathilda"

Forward: "4 way intersection with Bordeaux and 2nd"

Forward: "Intersection with Caribbean, facing east on Caribbean" (Mathilda bends to the east and changes into Caribbean)

Forward: "4 way intersection with Borregas"

Right: "Facing south on Borregas"

Where Am I? "At 1393 Borregas, near the intersection of Borregas and Caribbean"

How Far? "1.52 miles traveled, .42 miles from last intersection"

We have just traveled around a rather large area in Sunnyvale,starting and ending our virtual trip near Arkenstone. At all points on our virtual journey, we could be asking for all sorts of information, such as:

How far have we walked from our starting point?

What direction are we facing?

What's the distance between this intersection and the last one?

What's the distance and direction from where we are now to any address we can specify in the region?

Describe this intersection in more detail.

Although these are interesting questions to be able to ask,there is another realm of information we need to use.

Personal Information: Overlays and Paths

Having access to city maps is quite useful, but not all geographic information is equal in value to each individual. One of the most valuable capabilities of Atlas Speaks is its ability to add information of special interest to the map database. In the first version of the system, this information comes in two forms: overlays and paths. Together, overlays and paths turn a map database into a personalized orientation tool that emphasizes the interests of the individual using the system.

Overlays are groups of points of interest. A point of interest is a location on the map with associated text information. Examples include home, work, a friend's home and an important subway entrance. Together, these points of interest add value to a standard area map by making it easy to locate places that are important.

We see these overlays becoming important units of shared information among users. One overlay might be all bus stops in a city or area. Another might be a list of hazards. Overlays of good restaurants, government services offices, a campus building directory and wheelchair accessible shops are all examples of geographic data of interest to groups of people.

Associated with overlays are paths. Paths are routes from one point to another. They are typically made up of a series of waypoints traversed in a certain direction. For instance, a short path of interest in the vicinity of Arkenstone is the path from the bus stop on Java to Arkenstone. The first waypoint is the bus stop itself, the second is the corner of Java and Borregas, the third is the corner of Caspian Court and Borregas and the final point is Arkenstone itself.

Paths are aids to orientation. A user who is interested in traveling to a new destination can use Atlas Speaks to find the destination. Next, they could find its distance to the closest point of interest in the user's overlays and explore different ways of travelling there. Questions like how close is it to different bus lines, subway stations and how much walking is involved can all be answered independently. Once a path is chosen, the important landmarks, intersections and turns for that path can be saved onto a tape recorder, Braille 'n Speak or hardcopy braille.

Comparisons to Other Access Techniques

The Atlas Speaks approach has some significant advantages in accessing map information compared to existing approaches. Where some approaches are stronger, Atlas Speaks generally has a straightforward means of cooperating with these to provide a solution that is greater than the sum of its parts.

The major advantages of the Atlas Speaks approach are generality, detail, dynamic range, cost, portability, independence and personalization. Most of these advantages stem from the electronic nature of the data. Since electronic GIS databases have considerable commercial value, they come in a form that is usable without requiring attention from specialized professionals or additional expense to make them usable. The dynamic range can be easily varied from a very small area to a high level view of an entire region. The level of detail depends only on the capacity of the electronic storage medium. Because the map database and application are software, they can be quite inexpensive for users who have a PC that meets the software's requirements. The cost of Atlas Speaks is projected to be under $500 (which includes the map of one region), and under $2000 including maps of the entire U.S. Software is also quite portable, since systems that can run Atlas Speaks weigh well under five pounds. Personalization is easy because there is no problem adding additional information to the map database.

Alternative methods of accessing map information include human assistance, tactile map output, softcopy Braille and Nomad. Human assistance is the most general, but is not always available when needed. The required dependence is also a significant disadvantage. Tactile maps in the form of raised line drawings have significant problems in the area of detail and dynamic range. Tactile resolution needs to be quite low, which means that either detail is sacrificed or the map is of a very small area. Softcopy Braille displays have been developed that can display tactile images, but they are quite expensive and likely to remain that way for some time. Nomad, a system where the user touches a tactile overlay on a graphic tablet and hears the text assigned to that area, has the most similar concept to the Atlas Speaks approach. It can be reconfigured for different overlays, assigning different text to different regions of the tablet. However, it does require design of each overlay, which makes it impractical for general map access.

Atlas Speaks is weaker than tactile displays for people looking for a way to visualize two-dimensional data. Although direction and distance information are available to build a mental idea of the relative positions of different points, tactile information makes these relationships easier to grasp. However, Atlas Speaks potentially makes it easier to put map information into tactile formats, since it can draw maps of any specified area of interest. We see users who have access to tactile output options using them with Atlas Speaks to examine areas of special interest.


Strider is a portable version of Atlas Speaks that combines the map database with location information. Strider will be an important orientation tool, but it is important to emphasize that it is not a mobility tool. Strider users have just as much need for mobility skills with a cane or guide dog, because information on location does not protect against the great majority of mobility hazards.

The Global Positioning System ("GPS") has a network of satellites that provide location information to users with specialized GPS receivers. Standard GPS receivers can locate a user within a three hundred foot radius of their actual position, which is useful information but not enough to always correctly identify the street the user is on. Techniques are being added to reduce this error to less than twenty feet, which would make the location information much more useful.

Paths, overlays and the other features of Atlas Speaks are also used in the Strider system. Instead of exploring an area in virtual reality, Strider combines the user's actual location with the ability to ask about the vicinity and points of interest.

For users in areas without street maps available, or for rural users where the features of interest are usually not roads, Strider offers the opportunity to build maps of paths and places by simply visiting them. Several visually impaired hikers and boaters have expressed strong interest in having these capabilities.

Plans for Atlas Speaks

Atlas Speaks is currently in prototype form and will be tested extensively by users during the summer of 1994. The first version for general availability is scheduled for fall of this year. This will include almost all of the United States. Visuaide 2000 will be working to make major Canadian metropolitan areas available in the same time frame. European maps are expected to begin to be available at the end of 1994. User feedback and experiences will determine many of the near-term improvements to Atlas Speaks.

The general technique of exploring a two-dimensional map database with text labels is not limited to maps. The same approach could be used for other graphic information. For instance, other GIS systems could be interfaced to render information other than simply location and addresses. An interface to census or political databases might offer demographic or political data accessible to blind users. The technology does not need to be limited to two dimensions. A current project to completely digitize the location of all parts of a human body in three dimensions could be made accessible to virtually examine anatomy using these techniques. The dynamic range could expand from the relative locations of major organs and structures to very tiny details of the heart.

Arkenstone and Visuaide 2000 are interested in making projects of this type practical.


Arkenstone and Visuaide 2000 have jointly developed a new approach to providing access to map information using virtual reality techniques. The system, Atlas Speaks, offers unprecedented capabilities to explore your neighborhood or any city of interest. The flexibility to annotate and expand the information in the map database gives users the power to personalize the information and make it more useful. Adding the location information derived from a GPS receiver creates the Strider portable orientation system, which offers real-time information about the trip in progress. These capabilities are the next major step towards personal independence for blind people in orientation and mobility.

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