DriverTrac/docs/UI_IMPROVEMENTS.md

World-Class UI & Alert Management Improvements

Problems Fixed

1. Alert State Management ✅

Problem: Alerts stayed ACTIVE forever once triggered, even when conditions cleared.

Solution: Implemented temporal smoothing with alert persistence tracking:

• Alerts clear automatically when conditions stop
• Configurable persistence frames for each alert type
• Smooth transitions between states

2. UI Improvements for Chromium/Raspberry Pi ✅

Problem:

• Emojis not visible in Chromium
• Poor visual feedback
• Unprofessional appearance

Solution:

• Removed emojis, replaced with CSS-based indicators
• Professional color-coded alert system
• Modern card-based layout
• Better visual hierarchy

Technical Implementation

Alert Persistence System

# Track how long alerts have been inactive
self.alert_persistence = {
    'Drowsiness': 0,
    'Distraction': 0,
    'Driver Absent': 0,
    'Phone Detected': 0,
    'No Seatbelt': 0,
}

# Frames to wait before clearing (temporal smoothing)
self.alert_clear_frames = {
    'Drowsiness': 10,  # ~0.3s at 30fps
    'Distraction': 8,
    'Driver Absent': 5,  # Immediate
    'Phone Detected': 5,
    'No Seatbelt': 8,
}

Alert Clearing Logic

if triggered:
    # Set alert active, reset counter
    self.alert_states[alert] = True
    self.alert_persistence[alert] = 0
else:
    # Increment counter, clear if threshold reached
    self.alert_persistence[alert] += 1
    if self.alert_persistence[alert] >= threshold:
        self.alert_states[alert] = False

UI Enhancements

CSS Styling

• Alert Active: Red border, light red background
• Alert Normal: Green border, light green background
• Status Badges: Color-coded pills (ACTIVE/Normal)
• Modern Cards: Clean, professional appearance
• Better Typography: Improved readability

Visual Indicators

• ACTIVE: Red badge with white text
• Normal: Green badge with white text
• No Emojis: Pure CSS/HTML for Chromium compatibility

Performance Optimizations

• Optimized YOLO inference (contiguous arrays)
• Faster image resizing (INTER_LINEAR)
• Log management (limit to 10 entries)
• Efficient frame processing

Benefits

User Experience

✅ Real-time feedback - Alerts clear when conditions stop ✅ Professional appearance - Modern, clean UI ✅ Better visibility - Color-coded status indicators ✅ Smooth transitions - No jarring state changes

Performance

✅ Faster inference - Optimized YOLO processing ✅ Lower memory - Limited log entries ✅ Better FPS - Improved frame processing

Reliability

✅ Accurate alerts - Temporal smoothing prevents false positives ✅ Consistent behavior - Alerts clear predictably ✅ Cross-platform - Works on Chromium/Raspberry Pi

Example Behavior

Phone Detection

1. Phone appears → Alert becomes ACTIVE (red)
2. Phone removed → Counter starts
3. After 5 frames (~0.17s) → Alert clears to Normal (green)

Drowsiness Detection

1. Eyes close → Alert becomes ACTIVE
2. Eyes open → Counter starts
3. After 10 frames (~0.3s) → Alert clears to Normal

This prevents flickering while ensuring alerts clear when conditions stop!