Twenty or 30 years ago, if you couldn't find your way on the road, you turned in to a service station and got turned on to a free map.

Now, finding the map may be a bigger problem.Folding the map seems like a small-potatoes problem these days, now that the free map business itself has folded.

At its height, in 1972 - when Sunoco was pumping that 100-plus-octane worth of pure tetraethyl leaded 260 into the air, when Roger Penske and Mark Donahue were on top of the motor sports world, when Watergate was Watergate and catalytic converters sounded more like a religious cult than a $300 emissions device - 250 million maps were printed. Most of them were given away in gasoline stations. Free.

Now the service station's free map is less common than a free air pump. In fact, it's extinct.

What happened?

Two situations, according to Conroy Erickson, spokesman for Rand-McNally, the undisputed heavyweight of map-dom: The fuel shortages of 1973-74 and 1979.

"The Arab oil embargo of '73-'74 made gas supplies scarce and prices much higher. Oil companies that had for several decades been distributing the free maps were trying to cut costs, and the customer was more concerned with the price of fuel than the availability of free maps," he said.

The free maps had a brief resurgence in the mid-to-late 1970s, but the second gasoline shortage in the summer of 1979, fueled by the Iranian Revolution, broke the $1-a-gallon barrier and killed the maps off for good.

They had a good, long run, starting in 1930, and were a peculiarly American phenomenon. In Europe, maps always have cost money, offered intricate detail and aren't updated often.

Not surprisingly, the dawn of map history was in 1906, with a map of what was called the King's Highway and is now the famous PCH (Pacific Coast Highway, Route 1) in Southern California.

On the East Coast, the first road map as such - it was a lot of black lines with no road identification - was of western Pennsylvania's Allegheny County, and Gulf and Shell handed out copies at their service stations.

The first map to identify roads by number was produced by Rand-McNally in 1917, and from then until 1930 (curiously, an almost-direct parallel with Prohibition), the dominant form of distribution was retail sales. You paid for it. Just like now.

By 1930, though, there were so many cars, so many roads and so many competitive oil companies that it got to be too hard to sell them. Free enterprise had the big oil giants wanting to give the maps away. And so began the 50-year era of The Free Road Map.

What of the future? Will the budding CRTs (cathode ray tubes - TV screens) with built-in navigation software eliminate paper road maps? How about the developing satellite navigation systems?

"Well, it can be quite amazing to see one of these (CRT) systems work, but then you look and say, 'Well, I've got to pay $1,500 or more to get this installed in my car. I can get a map to get around the city or wherever for a lot less than that,' " said Mr. Erickson.

And of the satellites? "If the federal government gets enough satellites up there to have 24-hour-a-day coverage of the entire United States, and if you have the ability not to have your satellite transmission blocked out by tall buildings or mountain passes and other things that may distort radio transmissions, you then can have a system that tracks where you are and feeds information back to you so you know where you are within 10 or 15 feet."

Mr. Erickson said this is the direction the trucking industry is taking, but it's got a long way to go before being perfected.

In the meantime, it looks like a long time before the $7.95 Rand-McNally Road Atlas, which is updated yearly, will have to worry about those folding problems.