Speed and Weight Limits Service¶
The Limits Configuration service allows you to define speed and weight thresholds for traffic analysis. When combined with speed estimation and vehicle classification, AITracker can identify vehicles that exceed these limits and generate statistical reports.
Overview¶
This service is designed for traffic studies and analysis - not for law enforcement. It provides valuable insights into:
- Speed compliance patterns
- Heavy vehicle traffic analysis
- Traffic safety assessments
- Before/after studies for road changes
⚠️ Important Disclaimer: Speed values are estimations based on trajectory analysis and homography transformation. Weight values are estimated based on vehicle category (not actual weighing). This data is not certified for legal enforcement or issuing fines/penalties.
Configuration¶
Limits Configuration¶
Speed and weight limits are configured in the VelocityConfig section of your scene configuration:
| Parameter | Type | Unit | Description |
|---|---|---|---|
day |
float | km/h | Speed limit for daytime hours (05:00-22:00) |
night |
float | km/h | Speed limit for nighttime hours (22:00-05:00) |
weight |
float | kg | Maximum allowed vehicle weight |
Time Periods¶
The system automatically distinguishes between:
- Day period: 05:00 - 22:00 (uses
dayspeed limit) - Night period: 22:00 - 05:00 (uses
nightspeed limit)
This allows for different speed limits during nighttime, which is common on many roads.
Speed Exceedance Detection¶
For each vehicle passing through the measurement zone:
- Speed is calculated based on time spent in the zone
- Current time determines which limit applies (day/night)
- Vehicle is flagged as
VelocityExceeded = Trueif speed > limit
Weight Limit Analysis¶
How Weight Is Estimated¶
Vehicle weight is not measured directly - it is estimated based on vehicle category:
| Vehicle Category | Estimated Weight |
|---|---|
| Motorcycle | ~200 kg |
| Passenger car | ~1,500 kg |
| Delivery van | ~2,500 kg |
| Light truck | ~7,500 kg |
| Medium truck | ~12,000 kg |
| Heavy truck | ~26,000 kg |
| Articulated truck | ~40,000 kg |
| Bus | ~15,000 kg |
Note: These are typical category weights. Actual vehicle weights may vary significantly. This is suitable only for statistical analysis.
Weight Exceedance Detection¶
The system flags vehicles as WeightExceeded = True when:
- Vehicle category's estimated weight > configured
weightlimit
This is useful for identifying heavy vehicle traffic patterns on roads with weight restrictions.
Weight Analysis Limitations¶
| Aspect | Description |
|---|---|
| Method | Category-based estimation (not actual weighing) |
| Accuracy | Approximate (based on vehicle type, not actual load) |
| Certification | ❌ Not suitable for enforcement |
Generated Reports¶
OffensesSpeed.png¶
Hourly chart showing: - Number of vehicles within speed limit - Number of vehicles exceeding speed limit
OffensesWeight.png¶
Hourly chart showing: - Number of vehicles within weight limit - Number of vehicles exceeding weight limit
Report.docx¶
The generated report includes:
Speed Limit Section¶
- Total vehicles analyzed
- Percentage of vehicles exceeding speed limit
- Day/night breakdown of exceedances
- Exceedances by direction
- Exceedances by vehicle category
Weight Limit Section¶
- Total vehicles analyzed
- Percentage of vehicles exceeding weight limit
- Breakdown by direction
- Heavy vehicle traffic patterns
Special Vehicles Detection¶
The system also identifies special vehicles (emergency, military, government) based on license plate patterns and reports them separately.