Being able to navigate is an important part of everyday life and difficulties in being able to do so are likely to affect people's opportunities for work and social inclusion and participation in general. However, people with visual impairment face difficulties when they navigate, because they have limitation in the main navigation sensor which is vision. This can lead to lack in information required for navigation including route planning, distance estimation and orientation although modern technology offers a means to help improve their ability to navigate independently . However, there is no currently available navigation system that is both universal and personal  to aid the navigation of visually impaired people based on their particular individual needs and preferences and indeed, routing algorithms typically inherited from satellite navigation devices tend to emphasise speed and efficiency over the selecting routes that blind people might find easiest or most safe to actually follow. For people with visual impairment, safety and independency of orientation and mobility are more important  than distance and time of a journey. Hence, it is important to investigate whether working with blind and partially sighted people's navigation related personal data both at individual and group levels, can be used to provide them with safe and preferred navigation for outdoor environment.
Technology provide a great opportunity for overcoming the barriers and provide independent travel for blind and partially sighted people. There are a considerable number of existing smartphone navigation applications for blind and partially sighted people such as RNIB Navigator , Eye-D -for visually impaired , Lazarillo GPS for Blind , Accessible Navigation ForBlind , GetThere GPS nav for blind , NowNav GPS Accessibility . If we consider these apps which are among the main apps designed for navigation of visually impaired people, we can spot the lack of consideration of the user preferences and needs in route selection and navigation guidance. As a result, the users may not experience a journey they prefer and might face difficulties while navigating.
Relatively little is known about the specific route preferences and requirements of blind and partially-sighted users compared to sighted users, particularly in terms of that can find expression in a routing algorithm capable of generating easier and safer routes relative to specific needs. Further, it is not known to what extent crowdsourcing routes already taken by blind and partially-sighted people might provide a way of informing the design of such a system and also if they might generalise to multiple blind and partially sighted users. It is an open empirical question as to whether pre-existing routing choices reflect accumulated wisdom of individuals and the crowd or whether they reflect limited, over-constrained choices that people could be aided in expanding upon [i.e., what is the balance between benefitting from more data and benefitting from better algorithms].
To what extent can the location history of multiple users be combined with the preferences of visually impaired people in a smartphone-based navigation system to provide a safe and personalised navigation system?
To investigate the factors that influence the route selection strategy of blind and partially sighted people and their natures and how that is different from route selection of sighted people.
To establish whether the combination of existing mapping and positioning technology, can be used to build a navigation system which meets the needs of blind and partially sighted users.
To design and test a navigation system for visually impaired people which incorporates crowdsourced route choices, identified route selection factors and relevant individual user preferences.
Investigate the factors that influence the route selection of visually impaired and sighted people based on the literature and interviews with blind and partially sighted people as well as certified O&M Instructors. In addition, creating user profiles which include necessary information for navigation.
Describe those factors and how their measurability and communicability might allow them to be incorporated into a navigation system.
Survey current positioning and navigation systems and techniques to describe the state of the art for practical, low-cost navigation systems.
Based upon the literature and interviews describe the navigation requirements of blind and partially sighted people.
Assess the strengths and weaknesses of current navigation systems against the identified requirements.
Develop a navigation system model which incorporates multiple users' location history, user preferences and previously identified route selection factors to address weaknesses in the state of the art.
Prototype and test an implementation of the developed model against the current state of the art navigation system. Testing might include computer simulation, Wizard of Oz Experiment and research in the wild.
This multidisciplinary PhD will contribute to enhancing the navigation of blind and partially sighted people in a new way by combining multiple users' location history with preferences and using smartphone as a practical and low-cost device to provide a safe and preferred navigation system.
It will contribute to knowledge concerning the user requirements, navigational preferences, and factors in navigational safety of the blind and partially-sighted who represent a relatively understudied group in society.
It will also contribute to knowledge in the area of navigational systems by exploring how crowdsourced route information can be used to design/feed algorithms that emphasise factors other than speed and efficiency (i.e., those that match the profiled needs of blind users and which emphasise ease and safety) and how users can interact with the resulting routes in navigation itself.
Finally, it will also explore methods for evaluating navigational experiences themselves (both aided and unaided) using criteria relating to safety and ease. All the above are likely to some extent to generalise to the understanding of navigation in general and how data about potentially idiosyncratic route preferences and prior routes taken can be integrated into a system to ultimately improve experience as well as just efficiency as is more commonly considered.
 M. C. Rodriguez-Sanchez, M. A. Moreno-Alvarez, E. Martin, S. Borromeo, and J. A. Hernandez-Tamames, "Accessible smartphones for blind users: A case study for a wayfinding system," Expert Syst. Appl., vol. 41, no. 16, pp. 7210-7222, Nov. 2014.
 V. Renaudin, A. Dommes, and M. Guilbot, "Engineering, Human, and Legal Challenges of Navigation Systems for Personal Mobility," IEEE Transactions on Intelligent Transportation Systems, vol. 18, no. 1, pp. 177-191, Jan-2017.
 K. Bozeman et al., O&M For Independent Living Strategies for teaching Orientation and Mobility to Older Adults. New York, New York, USA: AFB Press, 2015.
 Sendero Group LLC, "RNIB Navigator," 2014. [Online]. Available: https://itunes.apple.com/gb/app/rnib-navigator/id783866151?mt=8.
 GingerMind Technologies, "Eye-D -for visually impaired," 2015. [Online]. Available: https://play.google.com/store/apps/details?id=in.gingermind.eyed&hl=en.
 Lazarillo TEC SPA, "Lazarillo GPS for Blind," 2016. [Online]. Available: https://play.google.com/store/apps/details?id=com.lazarillo&hl=en.
 SAPRER ARIKAN YATEB, "Accessible Navigation ForBlind," 2016. [Online]. Available: https://play.google.com/store/apps/details?id=com.yateb.blindnavigation&hl=en.
 Lew Lasher, "GetThere GPS nav for blind," 2015. [Online]. Available: https://play.google.com/store/apps/details?id=com.LewLasher.getthere&hl=en.
 Les Smithson, "NowNav GPS Accessibility," 2015. [Online]. Available: https://play.google.com/store/apps/details?id=com.smithson.nownav&hl=en.
This author is supported by the Horizon Centre for Doctoral Training at the University of Nottingham (RCUK Grant No. EP/L015463/1) and Satellite Applications Catapult, Royal National Institute of Blind People.