Maps

When to use

• When location is a meaningful dimension of the data — for example, showing response volume by council ward, or mapping infrastructure projects by site
• Identifying spatial patterns that are lost in tables or bar charts (e.g., clustering of support or opposition in specific neighbourhoods)
• Presenting data to stakeholders who are oriented to geographic boundaries (government agencies, local councils)
• Engagement summary dashboards where decision-makers want to see which areas participated or which sites were prioritised

When not to use

• Don’t use when location isn’t meaningful — if the data doesn’t have inherent geographic structure, a bar or table communicates more clearly
• Don’t use choropleth maps for raw counts — large geographic regions appear more significant than small ones; normalise to population or a relevant denominator, or use a proportional symbol map instead
• Don’t use maps as a substitute for precise comparison — maps communicate spatial pattern, not exact values; supplement with a data table

Map types

Choropleth map

Fills geographic regions with colour to represent a value (e.g., response rate per LGA). Use a sequential or diverging colour ramp from the Orbit data visualisation palette. Never use a rainbow colour scale.

Point / marker map

Places individual markers at specific coordinates. Use for project locations, community facilities, or engagement event sites. Cluster markers when density is high to avoid visual overload.

Heat map

Visualises density of data points across a geographic area using a colour gradient. Useful for showing engagement density or footfall patterns. Apply the accessibility guidance for continuous colour scales in Colour in charts.

Accessibility

• Maps are not inherently accessible — interactive web maps require significant accessibility work. Every map must have a non-map alternative — a data table or list of the same information — reachable via keyboard without interacting with the map.
• Colour contrast for choropleth fills — Region fills must meet WCAG 1.4.11 non-text contrast (3:1) against the adjacent region colours and the background. See Colour in charts for compliant colour ramps.
• Keyboard access — Each interactive region or marker should be keyboard focusable. On focus, announce the region name, value, and any relevant metadata.
• Don’t use colour alone — In choropleth maps, supplement colour with labels, patterns, or a clear legend. Users with colour vision deficiencies may not be able to distinguish closely ranked colour steps.
• Zoom and pan controls — All map controls (zoom, reset, layer toggles) must be keyboard operable and labelled with accessible names.