You are correct; as far as I understand the term it means the Waymo car kept pace with (stayed next to) the other car (Camry) such that the Camry could not merg

You are correct; as far as I understand the term it means the Waymo car kept pace with (stayed next to) the other car (Camry) such that the Camry could not merge. I am also confused why the Camry could not just slow down and merge behind, but we don't have enough information to make any kind of determination.