GPS tracking has become an essential tool in the construction materials supply chain. It offers distributors real-time visibility, route optimization, and better communication with both drivers and customers. But installing GPS trackers is only the beginning. To improve delivery accuracy in a meaningful way, you must monitor the right KPIs (Key Performance Indicators).
Tracking the right performance metrics allows you to turn GPS data into actionable insights, reduce missed deliveries, and streamline operations across your fleet.
Here are the top KPIs to monitor to ensure your GPS tracking system is truly improving delivery accuracy.
- On-Time Delivery Rate
Why it matters:
The primary goal of GPS tracking is to improve how reliably deliveries arrive within the promised time window.
How to measure:
Percentage of deliveries completed within the scheduled time frame, tracked automatically via geofencing or GPS timestamps.
Use this KPI to: Identify regions, routes, or drivers with recurring delays and optimize schedules accordingly.
- Route Deviation Frequency
Why it matters:
Unplanned detours can lead to delays, confusion at job sites, and higher fuel costs.
How to measure:
Track how often drivers deviate from the assigned route without authorization or operational need.
Use this KPI to: Flag deviations for review, retrain drivers, or improve route planning accuracy.
- Estimated vs. Actual Time of Arrival (ETA Accuracy)
Why it matters:
Providing accurate ETAs to job sites builds trust with contractors and allows for better site coordination.
How to measure:
Compare the estimated time of arrival with the actual arrival time for each delivery.
Use this KPI to: Refine route planning tools, update delivery windows, and improve customer communication workflows.
- Idle Time During Delivery Routes
Why it matters:
Excessive idle time can indicate delays, inefficient scheduling, or problems at the job site.
How to measure:
Total time a vehicle is stationary during active delivery routes, as tracked by GPS and engine status.
Use this KPI to: Reduce wasted fuel, improve driver productivity, and streamline job site drop-off processes.
- Delivery Completion Verification Rate
Why it matters:
Proof of delivery (POD) tied to GPS coordinates confirms that materials were delivered to the correct location.
How to measure:
Percentage of deliveries completed with GPS-verified POD (e.g., geotagged photo, timestamp, digital signature).
Use this KPI to: Ensure accountability, reduce customer disputes, and confirm delivery accuracy.
- Missed or Failed Delivery Rate
Why it matters:
Missed or failed deliveries lead to job site delays, return trips, and lost revenue.
How to measure:
Percentage of deliveries that failed due to incorrect address, inability to access site, or lack of confirmation.
Use this KPI to: Pinpoint recurring issues and use GPS data to identify the root causes (e.g., wrong location, timing mismatch).
- Driver Adherence to Delivery Schedule
Why it matters:
GPS allows you to see not just where a delivery occurred, but when—and whether it aligned with expectations.
How to measure:
Track actual driver activity against scheduled stops and delivery time blocks.
Use this KPI to: Improve schedule reliability and identify gaps in training or communication.
- Geofence Compliance Rate
Why it matters:
Setting geofences around job sites allows for automated arrival/departure tracking and delivery confirmation.
How to measure:
Percentage of deliveries that trigger geofence entry/exit events as expected.
Use this KPI to: Automate status updates and validate whether materials were delivered to the correct site.
- Customer Notification Accuracy and Timing
Why it matters:
Timely updates build contractor trust and reduce inbound calls asking, “Where’s my delivery?”
How to measure:
Track whether GPS-triggered alerts (texts, emails, portal updates) are sent correctly and within the appropriate time frame.
Use this KPI to: Ensure your communication workflows are synced with your GPS tracking platform.
- Average Time Spent at Delivery Sites
Why it matters:
Delivery site efficiency directly impacts route completion rates and total delivery capacity per day.
How to measure:
Calculate the average dwell time at job sites using GPS-based arrival and departure data.
Use this KPI to: Identify which sites consistently cause delays and address root causes with contractors.
Final Thoughts
GPS tracking offers the foundation for smarter fleet operations—but it’s the KPIs you monitor that determine whether you’re improving delivery accuracy. By focusing on performance metrics that align with your customer experience and operational goals, you can go beyond basic tracking and build a logistics operation that is predictable, transparent, and scalable.
