"isn't that why we pay taxes?"
well, maybe that's what you'd like your tax money to be spent on. but you're being a little presumptuous. not everybody that uses the roads pays taxes, and not everybody that pays taxes uses the roads.
reality check: while i'm not currently paying taxes (i get way more back in rebates than i pay), i have paid taxes in the past. i don't even have a driver's license. and, i think this is becoming a lot more common with younger people, especially younger people in the cities.
if i were to stand up and say "i pay taxes. shouldn't i get on the bus and the subway and the light rail for free? i mean, that's why i pay taxes, isn't it?", i'd likely get eye rolls. but, it is fundamentally the same argument. i use public transportation and am expected to pay for it. i'm also expected to subsidize highways that i don't use. where's the reciprocity in this?
i think a just solution can happen in one of two ways:
1) we neither have toll booths on highways nor do we have toll booths on subways or buses or light rail.
2) we have toll booths on highways, just like we have toll booths on subways and buses and light rail.
i prefer the first option. but, my opposition to the second is not going to be so high - not so long as i have to pay to get on the bus.
http://www.theglobeandmail.com/globe-drive/news/trans-canada-highway/road-tolls-will-they-actually-reduce-congestion/article32974843/
if, in the end, we end up using toll booth revenue to fund public transit? that's some wealth redistribution in the right direction...