About 40 million visually impaired people live around the globe, forced to cope every day with challenges, especially when they have to cope with getting around. When walking, various environmental features pose danger – stairs, bicycles and cars, physical obstacles on the sidewalk, and more.
Blind pedestrians lack critical information about the space they traverse outside the familiarity of their home, making them restricted and dependent on others. Even if they have a white cane or a guide dog, these challenges seriously limit their mobility and independence, affecting their quality of life.
For most pedestrians, it is natural to choose the shortest, most convenient route, utilizing their innate wayfinding skills and perceptual and cognitive structures of space into spatial information. But for people who are blind or visually imaired, this so-called simple task is often complex and even dangerous.
Smartphone mobility applications, which mainly rely on the Global Navigation Satellite System (GNSS) sensor, help blind pedestrians to c carry out their daily activities, such as catching a bus (such as Step-Hear), reading road sign text and identifying their exact location (such as Sendero Group, GeorgiePhone).
There are other existing assistive technologies, such as electronic canes or the Israeli invention Or Cam (that can instantly read to the user text from a sign, smartphone screen or any other surface and even recognize faces) that improve visually impaired pedestrian mobility to some degree by indicating nearby road obstacles, but those technologies lack significant information about the surrounding space.
Researchers at the Technion-Israel Institute of Technology in Haifa have developed an innovative mapping system for blind pedestrians that communications with them by voice. The study was carried out by Achituv Cohen, a doctoral student in the transportation and geo-information engineering division of the Technion’s Faculty of Civil and Environmental Engineering under the supervision of Assistant Prof. Sagi Dalyot. It was just published in the journal Environment and Planning B: Urban Analytics and City Science under the title “Route planning for blind pedestrians using OpenStreetMap.”
The researchers looked into the possibility of using OpenStreetMap to map spatial data relevant to blind pedestrians while calculating optimized walking routes. OpenStreetMap is an open-source mapping infrastructure based on crowdsourcing of geographic data contributed by citizens all over the world that provides maximum flexibility through inserting, editing, analyzing and integrating accumulated mapping data and spatial information.
In the study, Achituv developed route-calculation software for generating walking routes adapted to the needs of blind pedestrians. The team performed in-depth investigations, observations, and interviews with orientation and mobility instructors, as well as with blind persons. The instructors were mainly from Migdal-Or, a non-profit organization that provides rehabilitation services for people with visual impairment or blindness throughout Israel.
These highly trained instructors have the knowledge and extensive experience in serving numerous blind people every year. The fieldwork resulted in a clear definition of spatial criteria that best reflect aspects of mobility, accessibility and safety, defined by geometric complexity of the route; route type and what it is used for; route length, and; landmarks along the route. The accessibility of traffic signals and other factors were also integrated.
The software weighs the environmental and semantic data that are important to the vision impaired, with an emphasis on safe, accessible, and navigable routes. These criteria enable qualitative and quantitative examination of the various available road segments between the starting point and the destination, determining the level of accessibility and safety, thus recommending the most optimized route to the user via a computerized voice.
The developed software was tested by blind volunteers and an orientation and mobility guide in several places. Not only were the routes recommended by the new software identical to the routes defined by an experienced guide, but the volunteers noted that, in most cases, the route chosen by the software was indeed more accessible and safer for walking than the routes calculated by existing commercial software, including Google Maps.
The OSM database, which can store large volumes and detailed sets of objects that are often missing in other mapping infrastructures, has the potential to serve as the mapping infrastructure for the computation of a tailored weighted network graph, they wrote. “Moreover, the fact that OSM offers communities the possibility to contribute to a meaningful cause, by completing missing data quickly and simply, elevates this methodology to a crowdsourced bottom-up model, in which anyone and everyone can take part.”
These findings show that the software is an effective and useful tool, improving the lives of visually impaired individuals in terms of mobility, accessibility and independence
Nevertheless, the authors continued, OSM has some shortcomings, mainly in terms of data quality (such and accuracy and topological errors) and completeness; still, current research shows that OSM road network geometric and topologic attributes are mostly accurate and up-to-date in the majority of cities.
“This issue should be addressed to make the developed solution scalable, where one suggestion is to use external sources, such as online sources of street-level photographs, as well as machine and deep learning prediction models, to generate new and missing data. We also plan to investigate the inclusion of temporal effects, such as traffic flow and smell, on the solution. Another idea is to adjust the criteria weights via existing routes travelled by blind pedestrians or generated by orientation and mobility professionals. Moreover, we plan to carry out further experiments with additional participants, in order to extract a more encompassing and accurate qualitative assessment of our solution.”
They concluded that “these findings have the potential to improve the quality of life of blind pedestrians – by enhancing their independence through their increased ability to safely wayfinding in urban environments. In turn, this could make a significant social contribution to the blind community, empowering this population as they maintain a healthy and active lifestyle, become a part of society, and join the workforce. This will also contribute to the general public, who will have increased interaction with blind people. Additionally, the understanding achieved from this study could be integrated into urban planning, for ensuring accessible designs and walkable cities for blind pedestrians and other populations with disabilities.”