If the vision stack is just below its certainty threshold that a car is coming across at 63mph at some angle and can't quite decide to take action on its own, and at the same time radar indicates a car is coming across at the predicted angle and speed, it should push it over the threshold, even if it might get false positives from overhead bridge traffic Lining up with the vision estimate makes that less likely, and the vision stack itself can also be used to exclude data that might be from an overhead bridge by detecting that there is no bridge nearby.