Let's assume there are 15 million people with California licenses. It feels like a lowball, and I only want to do an order of magnitude approximation.
Let's assume the DMV prints licenses every business day in a year - about 250 days. Let's assume that IDs last for 4 years.
That means, once every 1000 DMV-days, you need a new license. 15 million people * (1 license per person per 1000 dmv days) = 15,000 licenses per DMV day.
That is just plain amazing throughput on new licensing.
I've also been spending a lot of time thinking about the sorting procedures for the US Post Office. I can see roughly how FedEx works by online tracking. But the USPS' magnitude is just staggering. I know lots is handled without human interaction. Still stunning.