Road direction at intersection?

[ziruizhuang]

1.

From documentation: https://kddcup2021-citybrainchallenge.readthedocs.io/en/latest/cbengine.html#road-network-data We can see that the following road net info translates into intersection 42167350405 having a western approach 105.

42167350405 56 97 45 105

It means that for intersection 42167350405, road segment 105 is the Road_8 or inroad3, and 105's lanes are lane10,lane11,lane12 or inroad3lane0,inroad3lane1,inroad3lane2, with direction inbound to the intersection.

However, the simulation engine gives different definition:

For vehicle at road 105's lane 1,

{vehicle_id}, {road}, {lane}, {distance}, {speed}, {start_time}, {t_ff}
0,            105,    1,      12.0,       6.0,     26.0,         77.976

the simulator gives lane_vehicle_number as

{intersection_id}, {lane_vehicle_number}
22372852612 Environment vehicle number:  [0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
42167350405 Environment vehicle number:  [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0]

which means that the vehicle is on intersection 42167350405's lane23 or outroad3lane1, with direction outbound from the intersection, per documentation at https://kddcup2021-citybrainchallenge.readthedocs.io/en/latest/APIs.html#simulation-step.

The directions from simulation seem to be the exact opposite of the ones in documentation.

2.

In https://kddcup2021-citybrainchallenge.readthedocs.io/en/latest/cbengine.html#road-network-data , there are two directions, dir1 and dir2. Could the documentation clarify which direction (dir1 or dir2) indicates the direction from source intersection to destination intersection?

[zhyliu00]

Thanks for your advice. We have updated the doc.