  This technical report presents the online and real-time 2D and 3D
multi-object tracking (MOT) algorithms that reached the 1st places on both
Waymo Open Dataset 2D tracking and 3D tracking challenges. An efficient and
pragmatic online tracking-by-detection framework named HorizonMOT is proposed
for camera-based 2D tracking in the image space and LiDAR-based 3D tracking in
the 3D world space. Within the tracking-by-detection paradigm, our trackers
leverage our high-performing detectors used in the 2D/3D detection challenges
and achieved 45.13% 2D MOTA/L2 and 63.45% 3D MOTA/L2 in the 2D/3D tracking
challenges.
