We were somewhere around Beltsville with the hammer down when the eyes glazed over and the brain locked up hard. To diagnose it simply, it had had quite enough of the Beltway.And when a brain decides to strike at 65 mph, seatbelts notwithstanding, lives are in danger. There was no choice but to puuuuuuuuuuuull over.

For a stranger on a strange road, the Beltway is 66 miles of curlicue anxiety. It dips and rolls around the capital, through Maryland and Virginia, crosses the Potomac in two places, and becomes, in effect, a merry-go-round of madness: four lanes of fools go one way and four lanes go the other.

Exist whiz past - anaesthetic green signposts, seductive as aPopular Mechanic bed of spikes. Strangers can only fantasize what must lie beyond. . .

What is this "Beltsvill" exit, anyway? Perhaps. . . a factory town of ruddy-faced men, grimy yellow Caterpillar caps pulled down hard to hide bloodshot eyes, their calloused hands punching out a rhythm of holes in cowhide belts . . . and, over the plant radios, Johnny Cash moaning sympathy for their devils: infidelity, Jim Beam and lonely women in trailer parks . . . Why not, instead of Beltsville, an eight-foot rawhide strip branded, in red, and stretched across the highway to announce BELT CITY?

"Snap out of it!" screamed my wife.

"You're driving on the shoulder! "

"Great highway," I grimmed. "Five roomy lanes, heh, heh . . . "

Vrooooooooooooooom, the fantasy is gone, and another milepost slips into view. There is little else to peruse.

Meanwhile, the brain turns to soup.

As dogs sniff their brothers, drivers pass each other and stare. Faces look frightened, bored, anticipatory - as if they would do anything to get off the Beltway. It takes bravado to cross over to the other side. And until they exist, idle hands have nothing else to do except turn up the radio and threaten each other with 4,000-pound death machines.

"WATCH OUT!"

I swerve to avoid hitting one of those hideous black alligators swarming up from the Potomac for his afternoon snack. . .

"Don't look like alligators to me," said my wife.

"Could be mangy retreads," I said. "Likely blown off the road by some 18-wheeler with Jabberjock Benny at the wheel. They take on all sorts of shapes if you're trapped on the Beltway too long. Like clouds."

The sun bounces bumper to bumper, blinding, turning the lanes into strobe alleys. Trees whir past; shiny wax jobs become forests of reflection.

A man in a gold Cadillac pulls alongside and starts making faces. Does he want to play bumper cars?Why not. I nudge the auto toward him. Life itself seems to flash before his eyes and, from behind push-button windows, he appears to curse. Boredom always was the Devil's good buddy.

We have Lady Bird Johnson to thank for this. She banished billboards from these hula hoops of concrete monotony. Sure, they were eyesores, but they kept us awake. Of course, every billboard led to some shyster's American Dream. But nowadays, it's a wonder people can find their way home.

Remember "See Rock City?" Well, you won't see it painted on barns along the Beltway. Nor billboards touting Aunt Fanny's Banana Fritters. Without a highway jubilation to get the mouth salivating a few miles off, it's a lucky stranger indeed who stumbles off I-495 at Georgia Avenue, in desperation, and winds up straddling a tasty Reubenopolis (hot corned beef, melted Swiss, cole slaw and Russian dressing) at Gus Haris's Woodside Deli, a short jog off the Beltway at 9392 Georgia Ave.

We had littered up the auto pretty bad by this time and were grateful to find a friend in "The Big Sucker." It looked surly, menacing - a giant vacuum cleaner that squatted outside the car wash across from Gus's place. Was this the rotund, runaway child of R2-D2 and Otto the Orkin Man we'd been hearing about over the CB?

"Don't get too close," I warned. "It might try to pick your pocket."

"Are you feeling all right?" asked my wife.

The B.S. gobbled up our trash as if it hadn't eaten in weeks.

Along with sloth, the Beltway breeds a fear and loathing all its own - and people who spend too much time out here begin to wear their hearts on their bumpers: "I'm not deaf, I'm ignoring you. . . My take-home pay won't take me home. . . Truckers are great lovers," etc.

You pay attention to rear ends when all you get to look at are flowers and trees. Pines and petunias can get pretty boring if you are, as we were, trapped on the Beltway, slaves to the Cruise Control, a freeze-dried brain behind the wheel!

Six hours we'd been circling it now, in a clockwise direction, venturing off where the spirit moved.

Sometimes, a CB radio can be a good buddy. "Break, one-nine!"

"Go, breaker, fer golly's sake, you shore sound like you need a break fer shore!"

"I ain't alone, good buddy, look out yer window," I said.

Indeed. Everyday, more than 108,000 people zoom past the Georgia Avenue portion of the Beltway in Maryland, and to those who regularly counsel their buddies, it's easy to spot The Beltway Blues by the tone of voice.

The Beltway has been called a 66-mile obstacle course. And in Montgomery County, police have nicknamed a bothersome stretch between Georgia and Wisconsin Avenues, "The Rock Creek Roller Coaster," for the way the eight lanes rise and fall across the park.

Walt Disney's Fantasyland appears to leap straight out of the forest - an awesome castle of white marble and gold - which is, in fact, the Mormon Temple. More than one Beltway-bored Jello-brain, it is said, has come round the quiet turn and, whamo, nearly gone to heaven rubbernecking at the sight.

On again, off again. We find Pablo Furman, a District grocer, sitting perfectly still under a beech tree at Exit 28, sipping green tea with his family. He has the day off. The Beltway isn't nearly as bothersome as life in Argentina.

"I went back six months ago," he said. "It never changes. You wake up one morning and everthing has gone up 300 percent. A new car costs $20,000. Salaries are terrible. Everyone is passing bad checks. People can barely pay their rent and put in a few pesos in their pockets. In this country you throw away things people down there would love."

"But what about crime in the cities?" I asked. "What about our Beltway?"

"America makes some big mistakes," he said. "But America is a big country. I like it here just fine.It's a free country. You can do what you please. . ."

After the pain of Argentina, the Beltway seems hunky-dory - for a minute. Then I notice a huge, black carrion bird circling overhead, and wonder if it feels trapped above the Beltway.

We do another turn, reverse directions and start swimming against the tide. Round and round, couterclockwise now. We need a friend. At Exit 34, the Maryland State Police Barracks, we find one - the Beltway's Daniel Boone. It is not love at first sight, but greeting strangers fresh off the Beltway does not always come easy.

Let's say a sweating, bald-headed man, his biceps taut from gripping the wheel too hard, slams the car door and comes at you, twitching, in the heat of the day. It's enough to make any man catch his breath.

Tom Bowers isn't Anyman, but how is the Prince George's County detective to know the stranger isn't Abdul the Butcher, or some other mad dog, escaped off Live Atlanta Wrestling to roam free in The National's Capital?

Of course, he can't he sure. So he carries a steel-hard .38 on his hip. He's met strangers on roads far stranger than the Beltway. Bowers is taking no chances.

The cop shakes the stranger's trembling hand and says, man to man, he looks like he could use a belt at the Starlight, a topless beer joint off Exit 27. "They've got a lot of drunks who like to go in and yell at the nekkid women, sweaty girls who lean up against the mirror and watch the roaches crawl up their legs. Plenty of bikers go there We get a lot of fight calls. . . "

"Sounds like my kind of place," I said.

"No way," said my wife.

"Heck," said the cop. "Why don't you all just go ride around the Beltway?"

Back on the merry-go-round.

At Alexandria's back door, Exit 3, we consider giving it all up. George Kearns, 40, a-tobacco-chewing mechanic, says I have all the symptoms.He's seen it before. His junkyard is proof of what too many miles on the Beltway can do to a driver. One VW camper looks like King Kong's handball. It is not the first car Kearns has towed. There are others - abandoned intact. Some people get sick of driving, they just pull off the shoulder and walk away from it all.

Parting is not always so easy, and we are cheered to hear, over the CB, that love is still alive.

"Break for my Brown Sugar,"

"You got the Brown Sugar, and I can't wait 'til you get to my home twenty, Sugar Daddy. . . "

"Ohhhh, baby," another buddy butts in, "Why don't you ferget Sugar Daddy and try old Red Rooster. . . "

"He-haw," yells Sugar Daddy, "You ain't got enough manpower to handle MY Brown Sugar."

"No siree," says Red Rooster, "Twenty minutes with your Brown Sugar and she'd by MY Brown Sugar. . . "

"Ne-ga-tory!" says Sugar Daddy. "I'm her Sugar Daddy and she don't want no other. . . "

I drive another full circle and, bodaciously determined, leave the highway to buy a map. I am going to find a way off, one way or the other.