Driving scenario: Leading braking
Question: Is either the ego vehicle or the leading vehicle stationary?
Answer: Yes
Reasoning: Ego has a car stopped in front of him in his lane with its brake lights on, which he approaches until it stops for ego as well. He is on a two-lane road going in the same direction with no visible lines, with the car in his lane stopped in front of him and other cars on the left also stopped at the same traffic lights.