Introduction
Urban infrastructure in tropical cities faces two recurring hazards during rainy seasons: sudden road degradation (potholes) and severe localized flooding. Traditional citizen reporting systems rely on manual complaints, which are slow and reactive.
In this article, I share the architecture and engineering decisions behind RODA, an automated IoT-GIS system capable of identifying potholes and tracking street flood heights in real time.
1. Edge Sensing: Distinguishing Potholes from Speed Bumps
Using an MPU6050 6-axis IMU mounted near the vehicle suspension, vertical acceleration (a_z) is sampled at 200Hz. A common pitfall in vibration-based anomaly detection is false positives triggered by routine speed breakers.
To solve this:
- Derivative Thresholding: True potholes produce an initial sharp downward drop followed by high-frequency ringing (vertical jerk |Δa_z| > 2.8g within 40ms).
- Edge Vision Trigger: When an anomalous vibration spike occurs, the ESP32 signals an onboard camera to snap a roadway frame and upload it to our inference pipeline.
2. Edge-to-Cloud Computer Vision Pipeline
Running full-size vision models directly on microcontrollers is memory-prohibitive. We deployed a quantized YOLOv8n model on Hugging Face Inference API:
- The snapshot is transmitted via lightweight multipart HTTP POST.
- The model outputs bounding boxes and confidence scores for road damage classes (
pothole,alligator_crack,standing_water). - Only verified anomalies are committed to the cloud database.
3. Realtime Geospatial Mapping with Supabase & Leaflet
Each verified road anomaly is stored in Supabase with geographic coordinates, timestamps, and severity indices.
- PostGIS Extension: Enabled fast spatial queries to cluster nearby reports.
- Leaflet.js: Used in the frontend web portal to render interactive heatmaps and provide safe rerouting suggestions for commuters.
Conclusion
Combining low-cost edge hardware (under $25 per sensor node) with scalable serverless cloud APIs demonstrates that smart city monitoring can be built reliably without requiring prohibitive municipal infrastructure investments.