When you live in Pittsburgh and drive east across Pennsylvania, it costs you $22.50 if you take the turnpike all 302 miles to the Delaware River Bridge.

Live an hour or two north, though, and you have Interstate 80 as your go-to road for cross-state travel. It's free and clear until the Delaware.

I never gave that any thought until somebody told me I was getting ripped off. This person does public relations work for the Turnpike Commission, but he had a point.

Since July 2007, the turnpike has contributed $1.6 billion to PennDOT for roads, bridges and mass transit statewide. Not a dime of that $1.6 billion went to the turnpike, though it all comes from turnpike drivers, who saw tolls rise by 25 percent this year.

Meantime, northern riders on I-80 have kicked in bupkis beyond the gas tax.

The state has been trying to toll I-80 for two years with no luck. Pennsylvanians living along that highway, understandably, have fought for the status quo. It hasn't reached the point of raucous mobs in Du Bois or Stroudsburg, toting pitchforks as they emerge from pickups with "Ride Free or Die" bumper stickers, but it's early yet.

Last September, the Federal Highway Administration gave a long answer to I-80 tolls that can be summed up in a word: "No."

But the loaded words "at this time" were in the rejection letter, too.

The feds didn't think the state provided enough information about the market value of I-80, but some in Harrisburg think those questions can be answered and the Obama administration will allow the tolling.

The state Legislature's plan for funding highways and mass transit, Act 44, won't work without tolling I-80. It's based on the Turnpike Commission leasing the highway from PennDOT, collecting tolls and maintaining the road.

Until that happens, the scale is tipped against turnpike users. Not only do we have the indignity of driving through Breezewood, we have spent the past two fiscal years sending tens of millions of dollars in tolls into the state's northern counties to fix roads and bridges. We get nothing out of that deal unless, say, we drive up to Elk County to see the elk herd (quite a pretty trip, I must concede).

Some way or another, this inequity will be righted. Because the truly scary part is that the golden age of American driving is already fading in the rearview mirror.

That's a sad note to strike on a long Memorial Day weekend that, for so many, goes hand-in-glove-compartment with a long drive. Perhaps I'm prematurely nostalgic for the days when gas was cheap and roads were free, but it's pretty clear that's disappearing. Don't expect today's grade-schoolers to enjoy what we do by the time they start turning the ignition key.

The signs are there, right outside the gas stations. Even now, during a global recession, gasoline is $2.36 a gallon. What do you think it's going to be when the world's factories start churning again? Or when the dollar sinks as America slides ever deeper into debt? We can drill for more oil, but that won't be cheap, either. It's not as if that stuff is lying atop the ocean.

When we react to costly gasoline by buying more fuel-efficient cars, we can drive the same number of miles on fewer gallons of gasoline. But don't forget that the fuel tax is per gallon, which means the state will take in less money as we buy fewer gallons --even as we tear up the roads at the same pace. Highways are worn down by the miles driven across them, not the miles-per-gallon.

We could privatize the roads. We could raise the diesel tax to get more from the big trucks. We could put the lime in the coconut and drink 'em both together. But the current formula for highway construction is designed to fail, and it's just a matter of when.

The memo that went along with the rejection of I-80 tolls noted:

"The Federal Highway Administration is very mindful of Pennsylvania's transportation funding situation, which is not uncommon throughout the country. We commend Pennsylvania for thinking creatively ...

"As has been clear for some time, the U.S. Department of Transportation believes that states deserve broader flexibility to toll federal-aid highways than they are currently afforded under federal law."

Maybe that doesn't mean tolls from sea to shining sea, but it means more tolls somewhere, and soon.

So if you take a long drive this weekend, maybe to our beautiful, forested north, enjoy it but, above all, remember it. One day, you may want to tell your grandchildren how easily we all once got around.