In Freetown, it is estimated that more than 360,000 people live in informal settlements. These are vibrant and dynamic neighbourhoods of varying size, recency and characteristic. The residents of these settlements move between their own neighbourhoods and other parts of the city for economic and social reasons, but also to access services not available where they live.

As informal settlements often evolve without formal planning processes, the entry and exit points that connect them to adjacent neighbourhoods are not optimised. This means that some parts of informal settlements are very well served by access routes and some are poorly served.

For people with disabilities in informal settlements, a lack of proximate entry/exit points or inaccessible entry/exit points can greatly exacerbate the already challenging process of accessing essential services, economic opportunity or social networks.

Using recently acquired high-resolution drone imagery, OpenStreetMap data and community mapping methodologies, Humanitarian OpenStreetMap Team (HOT), Freetown City Council (FCC), National Commission for People with Disabilities - Sierra Leone (NCPD) and OpenStreetMap Sierra Leone (OSM SL) are collaborating to develop analysis methodologies to understand the status quo of access to seven informal settlements for disabled residents, as well as model how different proposed physical interventions could improve the access of people with disabilities to services and opportunities outside of the informal settlements in which they live.

The analysis uses open-source GIS (geospatial information systems) tools to evaluate the optimal walkability of persons with disabilities (PWDs) within the seven informal settlements to entry/exit points. The entry/exit points are bridges, crossways, and highways.

Alongside, open drone software — Drone Tasking Manager (Drone TM) and OpenDroneMap (ODM) — is used to capture and process the high-resolution imagery. The analysis also leverages several open mapping and open geo tools and databases, including:

• OpenStreetMap and OSM editors for digitising high-quality building datasets and Points of Interest (POIs).
• Mapillary for capturing and processing 360-degree images/videos to validate disability-friendly metrics on highways and entry/exit points.
• pgRouting for determining how long it takes to travel to entry/exit points from households and recommends the most efficient routes to be used by PWDs.
• uMap for visualising and sharing routing analysis for persons with disabilities (PWDs), providing relevant stakeholders with evidence-based insights to support decision-making.

The objective of this GIZ-funded project is to provide FCC with actionable information that will lead to improvement of entry/exit point infrastructure on the ground.

We propose to share with the State of the Map audience the co-design process, methodology, outcomes and limitations of this experimental analysis so that it can be improved and adapted in Freetown and other settings.