Oh to be clear I don't necessarily disagree, but albeit for different reasons - I think it's probably a more complex system than the motion based passing system installed on school buses. That doesn't mean that they'd be able to ignore what's happening "out of field" of what's immediately in front of the bus though - since it's a dynamic environment, and the system won't actually be able to know for certain that the bus is actually in the lane when it's passing stopped vehicles in bus stops/lanes, I'd think it'd have to scan the environment and process as a first order to determine those boundaries, to even determine if a possible offender is in fact encroaching. Since I'd expect that they do the compute on board, I'd actually expect that they perhaps don't have the compute power to actually process both lanes at once so it's probably virtually "fenced" to only process the imagery within its detection/ violation window, accounting for left/center/right running bus lanes - and it would have to be able to simultaneously distinguish lane markings and vehicles in that single pass for compute reasons. As the T has described it, that evidence package is generated on board and only the relevant segment is uploaded - it's reasonably computationally intensive, and I'd expect to happen as a second pass on recorded/saved footage after the first pass detects and flags the offender.
Edit: from SEPTA-Land, this is probably the best visualization I could find of what the computer sees, as I believe this is the same vendor the T contracted with - while it finds the lane edges for the buses direction of travel, and while it appears to disregard opposing lanes, it does identify vehicles in the opposing direction. Notably, this same vendor has an option to expand these bus mounted cameras to also conduct bike lane enforcement with the same onboard hardware. Hopefully, with the later success of the bus lane program, we can follow other municipalities in expanding it to bike lanes as well.
Santa Monica becomes first city to enforce bike lanes with Hayden AI technology installed on parking enforcement vehicles
www.hayden.ai