Calling this number from the California Department of Motor Vehicles is only recommended in specific situations. This is the number for the Mandatory Actions Unit of the California DMV, which deals with licenses that have been suspended for DUIs and other violations.
When calling this number, I was first directed to choose between English and Spanish. I was then left to choose whether my license was suspended because of a hearing or a DUI conviction. You aren't given any other choices at this stage, making it impossible to continue for assistance if you don't actually have a suspended license in California.
Just to check the menu, I went ahead and pressed the button for a DUI conviction and was told I should expect a longer wait-time than normal, and that there were 40 callers ahead of me at that time. I was told my call would be answered in the order received, and I could ask for a call-back number or choose to wait. Not having a legitimate DUI issue, I chose to hang up at that point, as I could not pose any legitimate question and didn't wish to have personal information attached to this kind of call.
Overall, I think it's smart for the state to have a line dedicated only to suspended licenses and their reinstatement. These tend to be complex, messy problems that lead to several steps for the driver in question to regain their privileges, and they often require personalized assistance. Given how complicated these issues can be, they can eat up large amounts of time, which can make it difficult for other customers to conduct the business they need to handle.
I also appreciated that the system told me exactly how many callers were ahead of me so I could decide to wait or request a call-back number. Often, the decision to wait or get a call back depends on how long it's going to take and whether the agent can make sure that they're going to be around when a call back comes. By offering this information up front, California makes it as easy as possible for customers to make sure they can get the help they need from a live representative.
It's impossible for me to say how effective the assistance from a representative is from this number, as I can only go off the automated system. But based on that experience, I would use this number if I legitimately had such an issue in California.