Notification theming

The Android Automotive OS (AAOS) notification system provides drivers with essential information while prioritizing road safety and minimizing distraction. This guide explains how you can customize car notifications and how they behave.

Design principles

Notifications in cars are optimized for glanceability and safety. Unlike mobile notifications, automotive notifications focus on simplicity:

  • Reduced complexity: Complex controls, such as long-pressing or intricate swipe gestures, are disabled to keep the driver's focus on the road.
  • Drive-state awareness: The system can automatically restrict or truncate content based on whether the vehicle is in motion.
  • Session-based: The notification list clears at the start of every drive to ensure that only current, relevant information is displayed.

How notifications appear

Notifications are delivered through two primary channels depending on their priority and category:

  • Heads-up notifications (HUNs): High-priority alerts that appear briefly over the current screen. These are used for time-sensitive information like incoming calls or navigation instructions.
  • Notification Center: A central hub where drivers can view a history of notifications they may have missed.

Customization

You can customize the notification experience to match your brand identity while maintaining core safety standards.

User interface and access

You can define how a driver accesses the Notification Center:

  • System shade: A menu similar to mobile devices.
  • Standalone screen: A dedicated UI accessed with a button in the system or navigation bar.

Visual styling

You can customize the look and feel of notification cards to align with your vehicle's design language:

  • Typography and color: Adjust fonts and color palettes for both day and night modes.
  • Shapes: Customize corner radii and container dimensions.
  • Motion: Define the arrival and dismissal animations for notification cards.

Priority and categories

The system categorizes notifications to determine how and when they are shown.

  • Car-specific categories: Includes CAR_EMERGENCY, CAR_WARNING, and CAR_INFORMATION for vehicle-status alerts.
  • Communication: Handles CALL and MESSAGE categories with optimized actions like "Play" and "Mute."
  • Navigation: Uses the NAVIGATION category to provide turn-by-turn guidance as HUNs only.

Next steps

To begin customizing notifications for your vehicle:

Style notification cards

Notification cards in Google built-in provide timely information to drivers while minimizing distraction. You can customize the visual style of these cards– including typography, color, and shape– to align with your brand identity while maintaining safety standards.

Notification card types

There are three primary versions of notification cards:

  • Heads-up notification (HUN): Appears briefly at the top (or bottom, depending on orientation) of the screen over the current app.
  • Notification Center card: Used for persistent notifications listed in the Notification Center.
  • Grouped-notification card: Combines multiple related notifications into a single, expandable card.

Card anatomy

Each card is a flexible container composed of four main areas:

  1. Header: Contains the app icon, app name, and optional timestamp.
  2. Content: Displays the notification title and supporting text (with optional message previews).
  3. Actions: Up to three buttons for user interaction (e.g., "Answer," "Mute").
  4. Large icon: An optional space for avatars or navigation symbols.

Styling guidelines

The following sections describe the styling guidelines.

Typography

You can customize the typeface and sizing to match your system's typographic scale. Use clear, legible fonts that perform well in varying light conditions.

  • Primary text: Typically 32dp (Body 1) for main headlines.
  • Secondary text: Typically 24dp (Body 3) for supporting info.
  • Fonts: While Roboto is the standard, OEMs can implement custom brand typefaces.

Color and elevation

Define separate color values for Day and Night modes to ensure legibility and contrast.

  • Card Background: Use distinct greys (e.g., Grey 868 for day, Grey 900 for night).
  • Text & Icons: Use high-opacity white (88%+) for primary information and reduced opacity (60–72%) for secondary details.
  • Accent Color: Apply the app's branding color to secondary icons or specific actions to help users identify the source.

Shape and spacing

Customize the physical boundaries of the card to fit your UI's design language.

  • Corner Radius: The default standard is 8dp (R2), but this can be adjusted for a more rounded or squared look.
  • Margins: Maintain consistent padding (standard 16dp or 24dp) between the card edges and internal elements.

Screen adaptation and drive state

Notification layouts must adapt to different screen dimensions (Standard, Wide, and Super-wide).

  • Drive State: When the vehicle is in motion, consider hiding message previews or truncating long text strings to reduce cognitive load.
  • Motion: Use standard arrival and dismissal animations (e.g., slide-down for HUNs, swipe-to-dismiss) to provide visual feedback.

Design the Notification Center

Drivers can view and manage notifications through this central hub that is designed for high glanceability and simplified interactions to meet safety guidelines.

Core functionality

Non-immediate notifications such as messages and reminders are available in the Notification Center. It does not store time-sensitive notifications like turn-by-turn navigation or active phone calls, which only appear as Heads-up Notifications (HUNs).

  • Session-based: The list clears automatically at the start of every drive to ensure the content remains relevant.
  • Priority-based: Notifications are ordered by importance (e.g., emergency alerts first) and then by recency.

Customization options

You can customize the Notification Center to align with your brand identity while adhering to safety standards

1. Access methods

You can define how users access the Notification Center based on your system's UI:

  • Pull-down shade: Users swipe down from the top of the screen to reveal the notifications.
  • Dedicated screen: Users tap a notification icon (usually a bell) in the system status bar or navigation bar.

2. Visual style

You can customize the following visual elements to match your brand's design language:

  • Color palette: Define distinct background and accent colors for Day and Night modes.
  • Typography: Set the font family, weight, and size for headers, titles, and body text.
  • Shape: Adjust the corner radii of notification cards and the overall container.
  • Layout: Customize margins, padding, and the vertical spacing between notification cards.

Interaction model

To minimize driver distraction, the interaction model is limited to essential actions:

  • Browse: A vertically scrolling list allows drivers to scan notifications.
  • Respond: Large hit targets for up to three action buttons (e.g., "Play," "Mute," "Reply").
  • Dismiss: Users can swipe a card to the left or right to remove it from the list.

Driving restrictions

The Notification Center must adapt to the vehicle's drive state to prevent cognitive overload.

  • Content truncation: The system can automatically truncate long text strings based on character limits you set.
  • Hiding summaries: You may choose to hide message previews or summaries while the car is in motion.
  • List length: The number of visible notifications can be capped to prevent excessive scrolling during a drive.

Design checklist

  • High contrast: Ensure text and icons meet accessibility standards for all lighting conditions.
  • Large hit targets: Design buttons and cards to be easily tappable without precise motor control.
  • Consistent branding: Apply the same customization rules across both the Notification Center and Heads-up Notifications (HUNs).

Sequence motions

In the car, motion is more than just an aesthetic choice; it's a functional cue that informs drivers without drawing their eyes away from the road for too long. Car makers can customize notification animations to ensure they feel integrated with the rest of the vehicle's software experience.

Principles of automotive motion

  • Informative, not distracting: Use motion to signal changes in state (like a new message), but keep it subtle enough to avoid startling the driver.
  • Safety first: Animations should be short and purposeful. Avoid "bouncy" or overly complex transitions that demand extended visual attention.
  • Consistency: Notification motions should match the physics of the rest of the infotainment system.

Key motion patterns

The key motion patterns are described in this section.

1. Heads-up notification (HUN) arrival

When a high-priority notification arrives, it uses a directional slide to enter the screen.

  • Top-down entry: The standard for most systems. The card slides in from the top edge.
  • Hinting: This motion subtly indicates that the Notification Center can be accessed by swiping down from the same edge.
  • Customization: You can adjust the entrance duration and the specific easing curve to match your brand's style.

2. Swipe-to-dismiss

Drivers can dismiss a HUN or a card in the Notification Center with a horizontal swipe.

  • Visual feedback: As the user drags the card, it should move 1:1 with their finger.
  • Exit motion: Once the swipe crosses the dismissal threshold, the card accelerates off-screen, and the remaining list items shift vertically to fill the gap.

3. Grouped-notification expansion

Related notifications (like multiple messages from a group chat) are often collapsed into a single card to save space.

  • Expansion: When tapped, the card should grow vertically to reveal individual messages.
  • Collapse: The reverse motion should be slightly faster than the expansion to help the driver return to their previous task quickly.

Timing and easing

Google recommends following Material Design easing standards, which emphasize a quick start and a smooth, gradual finish.

Attribute Recommended value

HUN entrance duration

250 ms – 400 ms

Dismissal speed

Fast (to provide immediate feedback)

Easing

Standard (accelerate quickly, decelerate slowly)

Best practices

  • Prioritize legibility: Ensure a high contrast ratio between text and card backgrounds.
  • Consistency: Use the same corner radii and spacing rules for both HUNs and Notification Center cards.
  • Minimalism: Keep actions simple and text concise; avoid complex layouts that require more than a glance to understand.