My question involves a traffic ticket from the state of: California

I was following my IPhone maps directions and didn't realize that the lane I was using to access the 110 freeway headed southbound out of downtown LA, was a carpool only ramp. As soon as I was on the freeway I quickly realized I was in the carpool lane and immediately got out but not before I was photographed and mailed a ticket.
Now I recently read that paying red-light camera tickets in LA County is voluntary and could be ignored if sent in the mail.
Does this ticket fall into the same category?
Since it was sent by mail, and not certified, how do they know it made it to my house?
Am I okay ignoring this like the red-light camera tickets?

Thanks for your help!!