That's because many people are actively against mass transit spending, preferring their personal cars and low taxes. I know it's a tough sell in many areas even with gas prices over $3 a gallon. Take this example from a friend in Phoenix a couple of years ago.

It takes a significant investment from the public that many are going to fight, but without real alternatives to the personal automobile, the inelastic demand for gasoline will continue until it reaches a break point and real demand destruction occurs through bankruptcy, repossession of cars/houses, unemployment, etc.

FYI, The light rail won. It's being built here now in PHoenix.
I know and that's great. I just thought it was funny to point out how people just love their freeways...
But hey, what better way to support the highway than to get all of the slow-poke light-rail-lovers off of it?  Right? ;)