how intersections connected

[tiefan]

Hey,guys. I noticed there's a vehicle with the following route:

route [3182.0, 2770.0, 3115.0, 279.0, 278.0, 148.0, 366.0, 62.0, 54.0, 14.0, 587.0, 339.0, 991.0, 5001.0, 5275.0, 4919.0]

the related intersection data is listed below:
22376825101 3179 3182 2866 2863
12376825111 2772 2770 3181 -1
21688832114 3616 3115 2768 2769

and the related road information is:
21688832114 12376825111 402.0 16.666666666666668 3 3 2769 2770
1 0 0 0 1 0 0 0 1
1 0 0 0 1 0 0 0 1
12376825111 22376825101 355.0 16.666666666666668 3 3 3181 3182
1 0 0 0 1 0 0 0 1
1 0 0 0 1 0 0 0 1

According to the intersection configuration, 3182 is the eastern out going road of intersection 22376825101, but 3181 is southern out going road of intersection 12376825111.According to the road configuration, 3182 and 3181 are pairs.
This means the eastern leg of the one intersection is the southern leg of another intersection, how could that happen?

[zhyliu00]

Thanks for your comment.
Because of the irregularity of the roadnet, the direction of roads connecting to an intersection is relative. You could refer to the visualization.

[tiefan]

Thanks for your comment.
Because of the irregularity of the roadnet, the direction of roads connecting to an intersection is relative. You could refer to the visualization.

Thanks for rely.
In this case, which lane should the vehicle take? turn left or go straight ahead?

[zhyliu00]

'turn left' or 'go straight' are decided by the order of roads connecting to an intersection. You can refer to https://kddcup2021-citybrainchallenge.readthedocs.io/en/latest/cbengine.html#actions

[Kanstarry9T]

If a vehicle wish to turn-left at the next intersection, it will choose the inner left-turn lane (lane-0) once it entered the approach the next intersection. We only use mandatory lane-change model to mitigate the randomness, dicretionary lane-change behavior in the middle of road segment is currently ignored.