The Groves subdivision

What it is

A streetmap of The Groves subdivision in Buckhorn, built in 2022. PNG-based map underneath, with a checkbox-curated pin overlay above. Cartesian via touch, polar on tap. Pin-as-datum at the centre of the viewport.

Why a raster base, and why that’s right here

The later maps in the family draw everything as addressable SVG, because their job is to let a non-sighted user explore the detailed space itself. The Groves does not work that way, and that is a deliberate, fit-for-purpose choice rather than a shortcoming. Here what matters are the pinned points of interest— where the properties are in the subdivision — not the detail of the streets around them. The map renders a raster base for sighted context, and the accessible, interactive layer is the pin overlay drawn on top: only the pins need to be addressable, focusable, and described, because only the pins are what the map is about.

This is the family’s working principle in miniature: there is no single right way to render an accessible map — the rendering should follow the job. The Groves answers “where are the properties, and what is near each one?”; the East Toronto streetmap and the terminal map answer “help me explore this whole space,” and pay the cost of making every feature addressable to do it.

Why this demo produced the polar finding

The simplicity is the point. Most accessible-mapping prototypes start by piling on features — POIs, accessibility tags, transit overlays — and the cognitive load of the feature set obscures whatever spatial-cognition decision is being made underneath. With residential streets and nothing else, the modality-conversion problem became visible: the sighted observer scans the map in two dimensions; the non-sighted user, hearing announcements sequentially, has nothing like a two-dimensional reference frame to hold those announcements in. The visual map is Cartesian. The audio experience the user inhabits is polar.

The finding generalised. It applies to a terminal’s gates and washrooms and a streetmap’s pubs and parks as much as to the Groves’ residential streets. The simplicity here is what made the generalisation visible; the richer demos use it without re-discovering it.

Dual-mode interaction

Touch users move their finger across the map and hear what is under the finger at each location. Cartesian. Direct. Keyboard and screen-reader users tap a POI (or a coordinate) and hear its surroundings described — (name, distance, compass direction) for nearby features, arranged in onion-skin order from the tapped point. Polar. Allocentric, in the spatial-cognition vocabulary: centred on a chosen reference point, declarative, exploratory.

The pin functions as four things at once: visual marker (sighted users see it at centre); polar origin (distances and directions resolve against it); datum (the map orbits the pin, not vice versa); and the user’s agent in the multi-agent CoP framing.

Try it

The live demo currently lives at bobd76.sg-host.com alongside the East Toronto streetmap on the same hosting. Pending the in-progress migration off SiteGround onto the OVH VPS, after which the demo moves to maps-groves.a11ybob.com and the link here updates.

The demo takes over keyboard navigation, focus management, and screen-reader announcements once opened; that is why it lives at its own URL rather than as an iframe on this page.

Source

GPL-3.0. Source: github.com/bobdodd/accessible-maps.