1994 Project Reports

Personal navigation and wayfinding for individuals with a range of disabilities

Eric E Sabelman, PhD; Charles G Burgar, MD; Gayle E Curtis, MS; Greg Goodrich, PhD; David L Jaffe, MS; Janice L McKinley, MA; Machiel Van der Loos, PhD; L Gene Apple, PhD

Office buildings, hospitals and other large structures can be difficult to navigate for anyone, particularly those with impaired vision or limited mobility. The layout of such structures is often complex and difficult to understand, and the actual location of the destination person or office may change from visit to visit. In addition, the location of ramps, elevators and other accessibility features may be difficult to determine for an infrequent visitor. A series of preliminary projects have addressed this need for wayfinding and navigation assistance, each taking a different approach.

Responsive Environment

EE Sabelman, CG Burgar, GE Curtis, GE Goodrich, DL Jaffe, JL McKinley, HFM Van der Loos

The objective of this project was to investigate the requirements and feasibility of a responsive environment as a means for providing navigation assistance to individuals having a range of disabilities. The Responsive Environment (RE) system would provide transparent navigation communication to a traveler in a large building complex or public facility by sensing their presence and communication needs and then responding accordingly. The RE would present information to the traveler in an appropriate modality, with voice messaging provided for a blind traveler, for example, and large-print displays provided for one with low vision.

To characterize the need and obtain feedback from potential users, we convened a focus group with clinicians, Orientation and Mobility specialists, and visually impaired individuals. In this focus group we described the proposed system and elicited comments and concerns from the participants. The group offered a number of general guidelines for someone finding their way in an unfamiliar place such as an airport, based on the experience of the O&M specialists and accomplished blind travelers. This group expressed the following guidelines for visually impaired travelers:

• Take the time to learn routes and cues for places you will travel frequently.
• To orient in a new place, use other senses, like the smell of a bookstore or restaurant.
• Gather information ahead of time to preplan the route.
• In complex environments, seek sighted assistance, such as at a ticket counter in an airport.
• Double check all along the way; verify the directions given.
• Have a fail-safe location to fall back on and get reoriented.
• If disoriented, find an open door where someone might give directions.

In addition, there was a general consensus that wayfinding assistance should be available at several levels of detail in order to be useful for a wide population and in a realistic range of situations. For example, a system might offer point-to-point prompting along a route as well as a map-like verbal description of the layout of the space and the potential for a detailed query-response dialog in which the traveler might ask, "Where am I? What's down here? What is behind this door?"

Sound Guides

GE Curtis, MS, JL McKinley, MA, DL Jaffe, MS

The Sound Guides system is based on the concept that a blind or visually impaired person might usefully follow a distinctive sound or musical phrase as it ripples through the hallways of a building toward a selected destination. The traveler selects the destination at the entrance to the building, using a touch-tone phone or a touch screen display. A sound is then transmitted to speakers mounted in the hallways, activating them in the correct sequence to give the impression of movement toward a particular destination.

In 1992 a demonstration system was installed at the Western Blind Rehabilitation Center at the time of the 25th Anniversary open house there. Figure 1 shows the control interface for specifying sounds and sequences in the installation.This demonstration showed the feasibility of providing real-time automated wayfinding assistance. It also exposed specific problems that would need to be addressed in future work, such as the strange quality and unfamiliarity of the sound phrases and the need to localize the sound in the environment so that other building occupants are not disturbed or distracted.

Work on this project led us to look at other issues in wayfinding assistance, specifically those related to giving directions and the technologies that could be used to deliver such assistance. This approach would make use of the traveler's cognitive ability to form mental spatial models and to plan travel routes in advance of travel, relying on the technology to deliver directions information in spoken form as needed.

Republished from the 1994 Rehabilitation R&D Center Progress Report.