Back in 1950, on the rear cover of that great American institution called National Geographic, the national institution known as Coca-Cola ran an ad depicting the glorious future of America, a vision filled with smokestacks billowing the black wisps of vigorous industry, and ribbons of highways drifting off into amber waves of grain . . .

And then along came the conquering hero, the great Gen. Eisenhower, who as president created the Interstate Highway system to link north and south, east and west, and allow the wheels of industry to transport the products of free enterprise from points of supply to centers of demand.

Yes, fellow Americans, when Coca-Cola and Gen. Eisenhower looked into the future, they saw mighty roads filled with cars and trucks and vehicles of every description.

And now, 30 years later, with the Interstate Highway system virtually completed, a quarter-century after Jack Kerouac defined the essence of America as a tank full of 19-cents-a-gallon gas, and a clean windshield, and a V-8 humming down the road . . .

THERE'S NOBODY OUT THERE DRIVING!

This may be due to more than just the price of gas. You try to find regular unleaded and a windshield squeegee out there in the American heartland, two miles off Interstate 64, just as the sun is going down and right after the 1,432nd moth has splattered on the safety glass 16 inches before your very eyes.

Good luck.

What ever happened to the man who wore the star, the very one you could trust your car to -- not to mention Dinah Shore and all her Chevrolets?

Some potentially interesting observations from a recent cross-country jaunt:

* There seem to be more blown tires than vehicles on the road these days.

* Forget about finding single-viscosity motor oil. Don't even think about motor butter! Ask for a can of regular 30 weight, and the friendly cashier will generally hand you a pouring spout and, depending on the corporate proclivity of the particular station, Uniflo or something that Shell has wonderously called Fire & Ice, co-opting Charles Revson's sensual name for a red shade of lipstick.

* In the state of Kentucky, some hearses sport rotating red beacons.

* If you happen to be driving a little imported number--say, a Volkswagen -- and blow out the water pump in the middle of nowhere -- say, Paducah -- you will not be back on the road in four hours.

* The great dream of energy conservationists and neologists, Gasahol, is as scarce as little roadside cafe's, which in fact still exist but can only be seen and not reached from the interstate. The top of the exit ramp is almost always occupied by a Shoney's Big Boy.

* The other great dream of energy conservationists, diesel fuel, costs almost as much as gasoline.

* In such towns as Wentzville, Mo., the home of Chuck Berry, one can at 6 a.m. find homemade biscuits and red-eye gravy, which consists of bacon fat and coffee cooked together with flour in a cast-iron skillet. This concoction is said to immediately awaken body and mind.

* In Nashville, Tenn., would-be tunesmiths, guitars in hand, still wander around Music Row in search of elusive publishing and/or recording deals. This somehow seems as anachronistic as red-eye gravy.

* If the billboards are to be believed, Al Capone's 1928 bulletproof Cadillac is alive and well in Gatlinburg, Tenn., right up the road from the Heartbreak Hotel, which offers an Elvis Museum, queen-size beds and an ocean-wave pool.

* Do not ask for pasta in the Midwest; say macaroni, as in baked, usually with American cheese.

* In honor of the World's Fair, there is a new road sign on Interstate 81, near Strasburg, Va., which announces that Knoxville, Tenn., is 408 miles distant. There is no sign announcing that New York is even closer. Just up the road apiece, one can exit in Harrisonburg, Va., and discover next to the Greyhound terminal Ciro's New York Style Pizzeria, which stays open well into the night and is run by two brothers from Naples, Italy, who speak no English but seem to understand the difference between one person asking for pepperoni and another asking for green peppers.

* Columbia, Mo., is the only town in the United States that has an ordinance requiring the payment of a five-cent deposit on beer and soda cans. Some Columbia residents feel that this is inconvenient, even downright un-American. "If you can't buy a Coke, head out on the road and throw the can where you damn well please, what has this country come to?" a Columbian named Forest Rose asked in a bar one evening.

The next morning, on Interstate 70, inside the city limits of Columbia, a driver swerved to avoid another car. Although there was little traffic on the highway, the car collided with a gasoline truck, which exploded and tied up traffic for eight hours. One person was killed.

On the side of the road, several disposed-of Coke cans were charred by the intense heat from the explosion, which sent billowing black clouds of smoke up into the clear, blue midwestern sky.