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In-Car DAB+ Digital Radio - UX Guidelines In-Car DAB+ Digital Radio - UX Guidelines In-Car DAB+ Digital Radio

Design Principles

Design principles guide every layout, interaction, and content decision in the in-car radio interface. They ensure the experience is safe, predictable, and easy for drivers to use while their primary focus remains on the road.

Core principles

Section titled “Core principles”

Keep information current and easy to scan
Information must be accurate, up to date, and presented so drivers can understand the state of the system in a single glance.

Make content readable at a glance
Text, icons, and key states must be legible within seconds, in all lighting conditions and on all display types.

Use consistent language
Labels, messages, and terminology should be plain, predictable, and used consistently across the interface so drivers don’t have to relearn meanings.

Make targets easy to touch
Interactive elements must be large, well spaced, and easy to hit without precision, even when the vehicle is moving or vibrating.

Keep UI elements consistent
Icons, colors, layouts, and behaviors should follow predictable patterns so drivers can quickly recognize options and states.

The following sections expand on how these principles apply in practice.

What this means for design

Section titled “What this means for design”
  • Prioritize primary information like station name, playback state, and key navigation cues
  • Use legible sans-serif typography sized and weighted for fast recognition
  • Maintain strong contrast between text or icons and the background, with a minimum ratio of 4.5:1 and 7:1 for critical content
  • Avoid decorative imagery, detailed textures, or bright areas behind text that compete with content
  • Test designs in real conditions including bright sunlight, reflections, tunnels, dusk, and night modes to confirm legibility

Considered design reduces cognitive load and helps drivers quickly understand what’s happening so they can return their focus to the road.

Familiarity

Section titled “Familiarity”

Use established visual cues and behaviors that drivers already know.

Provide familiar actions, icons, and navigation. For example, let drivers set presets by “push and hold” or tapping a star icon, and list stations alphabetically.

Legibility

Section titled “Legibility”

If content isn’t legible, drivers will struggle to understand it.

  • Broadcasters must design content for legibility and relevance.
  • Manufacturers must optimize how content is displayed for legibility.

To achieve this, there needs to be a shared understanding of display environments and how content will appear.