Well, this is Colorado, so any time you want to increase taxes for anything, you pretty much have to put it to the voters. This is due to a horrible law called the Taxpayers' bill of Rights, or TABOR, which was itself approved by referendum, and engineered, proposed, and heavily promoted by a California transplant multi-millionaire slumlord named Douglas Bruce.

So, to be completely honest, at least big one highway project that I can think of was expensive enough that it did have to have a referendum to approve the funding (although technically that also included some light rail so maybe that's the real reason, LOL).

But in general, yeah, a roads budget is usually built into the general fund and just assumed that you're going to be spending lots and lots of money building roads. But getting rail approved is like pulling teeth.

The total costs of this rail project are supposed to be something like $14.5 billion, so in all honesty I wouldn't be super angry that it has to be voted on, but I get the sentiment in the above comment.

edit: dang it, again with the paragraphs. When will I learn?