Yes and no. When I'm in a city with mass transit, I use it. I have metro/bus passes from most major cities and keep them in a separate wallet for when I travel. Because I'm disabled, I can usually get an even better deal. The one exception is DC. A friend has a car rental service and gets HOT if I don't use his service when there. He gives me a great deal though, better then cabbies and is only a phone call away.
Where I live, the tribes have various buses for the different departments who will pick up clients and transport you pretty much anywhere if you call and notify them 24 hours ahead. I still have to drive 10 miles to get to a pick up point. One of the downsides of living in the boonies at the end of the dirt road!