Cars' FRR is often zero
Say you're riding the #3 bus up Burnet Road. You pay 50 cents to get on the bus. That's your "fare". As it turns out, if you consider all the money taken in and all the money spent out by Capital Metro, and divide the difference equally per trip, it actually costs the taxpayers a couple of bucks for your ride. (The #3 bus, because ridership is high, ends up subsidizing some other routes, but we're taking a simplistic view here). Your "farebox recovery ratio" is something like 20%.
Now say you're driving your Ford Explorer down Lamar Blvd. As I've been recently discussing in the transportation funding topic, no gas tax money is spent on roads like this in Austin (basically major roads that don't have a route shield on them).
Your "fare" for this trip is thus $0.00 (the road doesn't have tollbooths, of course). In other words, the only cost you pay directly at the time ("user fee") is the gas tax, but as noted, neither this road nor other major roads of this type in the city of Austin can be funded by gas tax dollars.
The cost of providing you with your rejuvenated driving surface was substantially more than zero (12.6 million dollars, including utility work), and all that cost was most recently paid by city of Austin taxpayers via property and sales taxes (bond election in '98). And don't fool yourself - most of the cost for projects like this isn't for pedestrians, cyclists, or bus riders. We'd have a much smaller and much cheaper transportation network if nobody drove -- the fact is that most of the money we spend on roads like this is directly attributable to people driving their cars, alone.
Your FRR on this trip is 0%. That's right, a big fat zero. The only time Capital Metro gets this bad is on Ozone Action Days. So, libertarians, perhaps you shouldn't throw stones from your suburban glass houses.
What about highways, you ask? Well, it's true the majority of funds required to build state highways do, in fact, come from the gas tax. There are other, less direct, costs of these roadways which are borne by society at large, but even when considering just direct construction and maintenance cost, you still don't get off claiming that you're paying the bills. A substantial portion (largest line-items, as a matter of fact) of both the 1998 and 2000 bond elections for Austin and Travis County's 2000 package were to pay "local contributions" towards right-of-way for new and expanded state highways. IE: even on a brand-new highway theoretically built with gas taxes, the property-owners and goods-buyers are still subsidizing you, whether they drive a lot, a little, or not at all.