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The first clue usually shows up in the replay itself. If the reconstructed path cuts a clean straight line between two points on either side of a stop, and the driver insists there was a real detour, a turn, or a long wait in between, you are looking at route replay data loss rather than a simple tunnel outage. A straight-line artifact means the GPS tracker never logged the points in between, so the software had nothing to draw with. When that gap lines up with a vehicle hard reset, a battery disconnect, or a device reboot during the route, treat it as a buffer problem, not a display glitch. This matters because a genuine signal gap in a tunnel still leaves buffered points that replay can recover once the connection returns. Route replay uses logged location data to reconstruct a vehicle's path after a signal gap, but it only works if the underlying vehicle telematics hardware has buffered GPS coordinates correctly during the outage. No buffer, no replay.Here is why power loss is so destructive. Most commercial trackers store location points in RAM before writing to flash memory. RAM needs power to hold anything. When a driver pulls the fuse, disconnects the battery for a repair, or the device hard resets mid-route, whatever had not yet been flushed to flash is gone. On a healthy device, points roll into flash every few seconds, so the window is small. On a device with a full buffer or slow write behavior, that window can stretch to minutes, and the replay will show a smooth, confident line that never happened. That is the dangerous part. The map looks clean, but the audit trail is fiction.To confirm the pattern, run a controlled test. Pick one vehicle, log its normal route, and simulate a power interruption at a known point, ideally during a short loop where you already know the true path. Restore power and let the device sync, then replay the trip. If points before the interruption survive and points right at the moment of the cut vanish, the buffer is writing too slowly or is already near capacity. Repeat the test at different points in the route. If losses cluster toward the end of a shift, that points to the data buffer filling up over the day rather than a firmware crash.Next, check configuration. Look at the log file size and buffer capacity settings on the GPS tracker. If the log is set smaller than a typical trip duration, the device overwrites old points and route replay loses the start of the route. Also review your server-side polling interval. Pushing updates every 5 seconds fleet-tracking-software-performance-a19ba9" class="faq-link faq-link-internal auto-internal-link">does not fix buffer loss and can increase signal latency on the cellular connection while draining battery on an asset tracker. A moderate interval with a solid device buffer usually beats aggressive polling.Firmware deserves a real look. Buffer management and flash write behavior are firmware responsibilities, and some versions handle power-loss recovery better than others. Check the installed version against the vendor's release notes rather than assuming every update fixes every buffer issue. Updates sometimes help, sometimes change defaults, and rarely excuse a hardware limit. If power-loss gaps repeat after a firmware check and a configuration tune, you are likely hitting a hardware boundary. The blog's own guidance is to replace hardware when missing route segments or idle engine inaccuracies persist for more than 10 percent of trips after replay. Fleet tracking at scale makes this worse; with 50 or more vehicles across a metro area, replay has to pull raw logs from each device and sync them with geofence alerts and compliance logs, so every lost buffer becomes a downstream reporting problem.Finally, document what your compliance logs actually require. Many accept signal gaps under 60 seconds, but thresholds vary by jurisdiction, and a gap longer than 5 minutes during a critical delivery window may not validate a service visit without an independent witness signature. Write down the gap pattern you see, note whether it correlates with power events, and keep that record with the trip. That way, when a customer or auditor asks why a route looks like a straight line, you can show whether it was a recoverable location data delay or permanent route replay data loss. That distinction is what keeps trust in your service visibility intact.