The permanent gas tax is an enormously important financial support for municipalities in this country. It is not indexed, so as inflation carries on into the future the value of that gas tax will diminish.
Secondly, the gas tax, while invaluable and predictable, which is a really important feature, is not sufficient for the size of investments required to bring our urban transit systems up to what I think we would consider modern, 21st century, competitive cities in a global context.