Description of TTC is lacking

[DreamyStranger]

In the documentation, the Time To Collision (TTC) observation is described as having shape V × L × H, where V represents velocity bins. However, it's unclear where these velocity values come from. The example uses velocities like 15 m/s, 20 m/s, and 25 m/s — are these values hardcoded? Can we customize or change them?

Additionally, the ego vehicle's speed in the TTC observation on highway ranges from about 12 m/s to 30 m/s (based on printed values). How does this range interact with the velocity bins in TTC? Shouldn't the central velocity bin always correspond to the ego vehicle’s current speed to maintain consistency?