Most days I drive in a car pool and utilize carpool lanes. I would think it would be valuable for WAZE if I could flag myself as carpool, so the traffic data is not skewed by me driving past non-car pool vehicles that are in traffic jams.

Ideally it would also use this to not re-route me if the carpool lane is moving well. Often times when there are accidents, the carpool lane slows, but keeps moving even though other lanes are at a standstill.