question about the invalid phase and the empty road warning.

[wangzelong0663]

result = self.eng.set_ttl_phase(agent_id,phase) if(result == -1 and self.warning_enable): print('Warnning: at step {} , agent {} switch to phase {} . Maybe empty road'.format(self.now_step,agent_id,phase))

My question what situation will the cause result to be -1？ Bacause each action/phase has two choices，such as the action 1 below, for the cars in the lane 1 or 7, they all can move. Is the lane 16-18 don't exist or the lane 22-24 don't exist will the 'result=-1'?(at lease one of them) Or only both the lane 16-18 and the lane 22-24 don't exist will the 'result=-1'?(both?) Hope you can understand what I mean, thanks.

[zhyliu00]

Thanks for your comment.

1. For the result of _set_ttlphase()，it depends on the existence of the source lane, not the destination lane.
2. When at least one of the source lane is -1, result will be -1

[wangzelong0663]

Thanks for you reply. That means if the lane 7 is not existence, if the action phase is 1 or 7, the result will be -1 ?

And I have one more question that I want to confirm that the something about the order of the obs:

the observations_for_agent[agent_id]['lane'] is 24 dims, which stands for the vehicle nums of each lane, and the order of the observations_for_agent[agent_id]['lane'] is same to the order of the lanes' num order in the image showed above (from lane 1 to lane 24)? And if the lane 7 don't exist, observations_for_agent[agent_id]['lane'][6] will be -1?

[wangzelong0663]

Sorry, I have one more question about this topic. If the lanes 16-18 don't exist, how the vehicles in the lane 9, 11, 1 move？ Or the vehicles cann't run into the lane 9, 11, 1, and the vehicle num of lane 9, 11, 1 will be zero if the lanes 16-18 don't exist?

[zhyliu00]

The vehicles usually won't run on 9,11,1 lanes unless this road is the last road of its route. You could refer to https://github.com/CityBrainChallenge/KDDCup2021-CityBrainChallenge-starter-kit/issues/17 Q4

[zhyliu00]

Thanks for you reply. That means if the lane 7 is not existence, if the action phase is 1 or 7, the result will be -1 ?

And I have one more question that I want to confirm that the something about the order of the obs:

the observations_for_agent[agent_id]['lane'] is 24 dims, which stands for the vehicle nums of each lane, and the order of the observations_for_agent[agent_id]['lane'] is same to the order of the lanes' num order in the image showed above (from lane 1 to lane 24)? And if the lane 7 don't exist, observations_for_agent[agent_id]['lane'][6] will be -1?

1. Yes
2. Yes. But the observation_features doesn't contain 'lane'. Do you refer to 'lane_speed' or 'lane_vehicle_num'?
3. observations_for_agent[agent_id]['lane_vehicle_num'][7] will be -1 because observations_for_agent[agent_id]['lane_vehicle_num'][0] is current step.

[wangzelong0663]

I mean lane_vehicle_num and thanks for reply,