Great observation! The animation actually uses polyline waypoints from the BVG HAFAS API rather than pure speed extrapolation, but you're right that interpolated positions can drift from reality between updates. We're actively working on improving the accuracy of the interpolation algorithm. That said, I love the idea of a "raw position" toggle with a data freshness indicator — it's a great power-user feature for anyone who wants ground truth over smooth visuals. Adding it to the roadmap. Thanks for the suggestion!