The default behavior of agents is now that they once started (left/forward/right action), they keep moving even if wrong actions (left/right) or do_nothing (action=0) are selected. Agents stop if they can't go forward (left-right only switch) or if they are explicitly stopped (new action 4).
Actions are now grouped into an int enum: class RailEnvActions(IntEnum): DO_NOTHING = 0 MOVE_LEFT = 1 MOVE_FORWARD = 2 MOVE_RIGHT = 3 STOP_MOVING = 4
Agents now have a 'moving' flag, that is True or False depending on whether they are moving or not.
Penalties for starting/stopping agents are implemented, but they are currently disabled (set to 0).