I'm doing some research for our roadtrip through SW USA (+Calif.) and ran into "carpool lanes" and this came to my attention:
Hopefully if you're not travelling alone, you will be allowed to drive through carpool lanes that help go past single-occupancy traffic
Since we're travelling with 2 (and part of the trip with 4), is it safe to say I can always use the carpool lanes? If more than 2 (e.g. 3) persons are required, is there a clear traffic sign that states this or do I have to know the rules in each state/city by heart?
I also found that 2 freeways in LA County (I-10 and I-110) were converted to toll roads and require RFID transponders. I suppose a rented car doesn't have a transponder? Is it made clear by any sign that you need a transponder?