Anaheim Disneyland to northbound I-5 on Friday evening?

We plan to leave Disneyland on Friday afternoon or evening and travel north on I-5. Not sure what the commute will be like at that time. Should we try to leave later rather than sooner to avoid traffic jams? Ideally, we would like to leave around 4 pm - but if that means having to wait in near stand-still traffic, I would much rather leave after 7 (or whatever time the traffic becomes better). Also, does I-5 have carpool lanes?