Frankly, I'd be concerned about the doctor who put you on a "maintenance med" regimen of Xanax. It's a med that can work well for some folks when taken on an as-needed basis (I've been on it this way for 10 years) but it's a [i]very[/i] bad idea to be on it continually as a maintenance medication for the very reason you found - a tolerance buildup.
Since my PA/PD revolves around driving, I need to take 0.25mg (even after 10 years, it still works effectively at this level) to make the 6 mile commute to work. Longer drives require up to 1.5mg per four or five hours of trip time.
I live by the simple rule that if I do not need to take it, I do not. It's addicitive. Your body can build up a tolerance to it. If that means I stay home one or two days a week (saturday and sunday), or risk having a PA/PD while driving around the block (a mile or two at most!), then so be it.
It's my opinion, based on what I know about Xanax from reading, observation, and discussion, that a healthcare provider who dictates Xanax as a maintenance medication is [i]not[/i] looking out for your long-term best interests and may not fully understand what havoc this benzo is capable of wreaking.
Xanax is one of the most powerful benzos available. Think of it as a gun. When handled safely and with understanding, it can save your life. When handled carelessly or with less than a full understanding of what it can do, it's exceptionally dangerous.
Just my opinion, but were I in your shoes, I'd find another doctor.
Be well~
