Lateral clearance is the right metric. Depth isn't.
Every public dashcam clip you've seen showing a close pass is reporting the wrong number. Here's why we don't.
When a cyclist talks about a close pass, they mean the side-to-side gap between their handlebar and the side of the vehicle that just overtook them. The rule the law cares about is the same: three feet, measured laterally.
So why do almost all bike-cam analysis tools report the wrong metric?
The easy number versus the right one
Most computer vision pipelines estimate distance from the camera to the back of the vehicle using bounding-box height or ground-plane projection. Both methods give you a usable depth estimate: how far ahead or behind the vehicle is. Neither tells you anything useful about how close the vehicle came to your handlebar.
A car can be twelve feet of "depth" away from a rear-mounted camera and only eighteen inches laterally from the rider. A car eighteen inches laterally from the rider is, by any reasonable definition, the kind of pass the law is trying to prevent. A depth-based metric will report that pass as "12 ft away." Same vehicle. Two completely different reads. Only one of them describes what actually happened.
How we measure it
Rydiq computes lateral clearance directly from the geometry of the bounding box, the horizon line in the frame, and the camera + mount calibration you set on upload. For every detected vehicle we use the bbox edge closest to the image center, project that pixel onto the ground plane with a pinhole model, and subtract a rider half-width. The result is a per-frame estimate of "how far is this vehicle from where you actually are."
It's not perfect. Wide-angle lens distortion at the frame edges, mount tilt, and partial occlusion can all shift the number. We surface a confidence band with every reading, and we publish a known-limitations list in the dashboard so you can weigh how much to trust a tight read on a particular clip. But the metric is at least the right one.
If you've been using another tool that reported close passes as "5 ft" or "8 ft" — check whether it was measuring depth or lateral. If it doesn't tell you, assume depth.