Designing Apps for Driving
Pleos Connect is software designed for mobility environments, providing optimized experiences tailored to different customers, vehicle models, countries, and brands. Use the guides provided by Pleos Connect to design apps optimized for the automotive experience.
Basic Design Principles
Usability & Safety
- Minimizing visual and cognitive load while driving ensures usability and safety through clear and simple information delivery.
- Do not draw the driver’s attention with videos, animated images, or automatic scrolling text while driving.
- App operations must be possible with one hand and should not require both hands. Only simple operations should be required. Do not prompt actions that require the driver to move their hands or feet.
Consistency
- Icons, terminology, and interaction patterns must be consistent.
- Utilize the design guide provided by Pleos Connect to maintain consistency with the built-in UI, reducing the user's learning curve.
Glanceability
- Provide information that is quickly visible and requires only simple interactions.
- Drivers must quickly grasp information within 1–2 seconds, so only essential information is displayed while unnecessary elements are excluded.
- System response time must not exceed 0.25 seconds after user input. If a response is delayed or takes time, visually indicate that the system is processing.
Interaction Principles for Driving Safety
The usability of touch interfaces in vehicles is a critical factor directly affecting driver safety. To enable intuitive and stable operation with one hand even in a moving vehicle, interface design must consider both driving conditions and ergonomic factors.
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Functions such as Search and Settings, which may distract the driver and interfere with safe driving, must be strictly disabled while the vehicle is in motion.
Minimize Distraction
- Display relevant information promptly and accurately during typical driving situations. Key information should be naturally conveyed within the driver's field of view using HUDs, clusters, and OSDs.
- Do not display moving images, videos, or animations while driving. Moving images can easily draw the driver's attention and pose a risk.
- Minimize the display of images that could interfere with driving. However, images may be displayed in the following cases.
- You can display one static image as the screen background for content context
Example: Album art, advertiser’s company logo
- Apps may display icons in the content browsing window.
- Navigation apps may display images for lane guidance or intersection directions.
- You can display one static image as the screen background for content context
Information Hierarchy
- Information needed while driving should be placed in the most intuitive locations.
Example: Navigation route guidance takes priority over media titles.
- Differentiate the driving state to restrict access to entertainment and detailed settings menus only when the vehicle is stopped or parked.
- App elements must not move automatically while driving. Ensure elements only execute and move upon user interaction.
- To minimize distractions while driving, prioritize visual and audio information accordingly. Prioritize crucial driving-related audio information, and ensure users can always mute the volume completely.
Example: When navigation voice guidance is active, media volume should be minimized or paused.
Touch Optimization
- Minimize touchscreen interactions and support interaction through voice commands and physical buttons.
- It must not encourage unnecessary, potentially dangerous, or distracting activities such as gaming, internet browsing, or fitness activities that involve hand or foot operation.
- Since touch interactions while driving are prone to inaccuracies, ensure sufficient spacing between buttons to minimize input errors.
- Button size should be at least 125 × 125mm to allow for intuitive touch interaction.
- Set the touch target slightly larger than the button itself to ensure proper recognition even if the touch input is slightly off-center.
Interface Design Guide
Color & Contrast
- Important information should have strong contrast, but excessive color usage should be avoided.
- Ensure sufficient contrast between background and text colors for clear visibility. The contrast ratio of icons, text, and other images must be at least 4.5:1.
Typography & Readability
- Minimize long text and convey information using simple icons and short sentences.
- A single English message or text must be no more than 120 characters (English) or 24 words (English).
- A single Japanese message or text must be no more than 30 characters (English).
- A single line of text must be no more than 80 characters (English).
- A sentence or paragraph must not exceed 3 lines of text.
- Maintain an appropriate font size based on the in-car display size and user distance.
- Key information (e.g., speed, navigation guidance, warning messages) should be at least 4mm tall, while general text should be at least 3mm to ensure quick readability while driving.
Icons & Feedback
- Use intuitive icons widely recognized internationally and accompany them with text labels for better understanding.
- Provide haptic feedback (vibration) or audio feedback upon touch interactions to enhance accuracy.
Notification
- Notifications must concisely deliver important information.
- The app must display notifications only when they are relevant to the driver’s needs.
- Notifications must not display advertisements, except for advertiser or product names.
Flexibility & Scalability Consideration
Night/Day Mode Support
Automatically adjust UI brightness and contrast to maintain readability based on lighting conditions during day and night.
Enhanced Voice Interaction
Pleos Connect supports voice interaction through Gleo AI. During app design, consider utilizing voice interaction to enhance usability and driving safety.
A voice-based communication system must allow hands-free speaking and listening. A hands-free voice interface may allow manual operation to start, end, or interrupt voice conversations.
OTA Updates
Consider Over-the-Air (OTA) updates for easy app updates and ensure continuous maintenance.
Scalability Consideration
- Pleos Connect is available in multiple countries, so we design the UI to support multiple languages.
- Pleos Connect supports various displays for different vehicle models. Therefore, we design with scalability in mind to accommodate various resolutions and aspect ratios flexibly.
