WHEN THE RUNNER HAD TUNNEL VISION, A POLICEMAN WAS A WELCOME SIGHT

"Would you mind running that by me again?" asked the bewildered policeman from his squad car. He had been dispatched late that November afternoon to the parking lot of an industrial plant on the outskirts of Mobile, Ala., where he was met by a tall, skinny backpacker in running shoes, babbling about jogging there from Pennsylvania and not taking rides and trying to get through a .62-mile highway tunnel. No wonder the poor policeman was confused.

"I'm sorry," the babbler said. Then he calmed down and told his story. It was the fall of 1979, and the fast-talking transient was I. After three years of selling computers in New York, I had traded in my briefcase and wing tips at the age of 25 for a backpack and Adidases, and had begun running a lap around the perimeter of the U.S. I'd started from my home-town of Mercersburg in the farmlands of Pennsylvania in August and reached the beaches of Florida in October; by the time I had jogged up to the shores of Mobile Bay it was mid-November. I'd covered 1,500 miles—all on foot.

"...but they won't let pedestrians through the tunnel," I was complaining, "and there's no other way to go into Mobile." A friend in the city was expecting me for the night, I explained. Did the policeman have any advice?

"Well, I don't know," he replied carefully. "I suppose you could go north over the Mobile River, but I wouldn't recommend it. It's about another 10 miles, and it's not the kind of place you'd want to run through by yourself. Especially not after dark." He offered to give me a ride.

I thanked him but declined. Couldn't I somehow get permission to go through the tunnel alone?

"Rules are rules," said the policeman, shaking his head. "If I were you, I'd take the ride. If you still want to walk through the tunnel in the morning, you can try talking to the authorities then."

Unfortunately, I'd already tried "talking" to them once. About an hour earlier—sweaty and exhausted from a 15-mile run—I'd been stopped cold at the tunnel entrance by a sign saying PEDESTRIANS PROHIBITED. Hoping to get an exemption, I'd slicked down my hair, positioned myself in front of a closed-circuit security camera and ingratiatingly presented my case. In pantomime.

Hi there! (I'd given a big smile and a little wave.)

I'm walking. (Two fingers walking along my forearm.)

Not hitching. (I mimed thumbing a ride, then shook my head, hands crisscrossing in front of my face.)

Want to walk. (Big smile, little walking fingers again.)

On catwalk. (I pointed to it.)

Thank you!

I'd mouthed the words, bowed and hopped up on the catwalk.

"Go back!" ordered a loudspeaker next to the camera. "Go back!" Crackling with static and ricocheting off the tiled walls, the command sounded like a burst from an ack-ack gun. "Pedestrians are prohibited! You will be put under arrest!" I'd thrown up my hands in mock surrender and headed north. A couple of miles up the road I'd come to the industrial plant; from its guardhouse I'd called the police.

"I'm telling you," the policeman continued, "when they say you can't run through the tunnel, and the signs are posted, you just can't do it." He paused and took a deep breath. "Don't you think maybe you ought to call it quits for today? You must be getting pretty cold."

I didn't want to admit it, but he was absolutely right. The sun was going down, my legs were growing stiff—I didn't have much choice. I swung the backpack off my shoulders and opened a door of the patrol car. But as I was about to get in, the policeman motioned me away.

"Wait a second," he said softly. "Just wait." He picked up his radio handset and called headquarters. "Get me the duty officer—whoever's in charge.... Thanks." He kept the microphone close to his mouth and stared out the windshield toward the plant. When the radio sputtered its response, the policeman spoke again.

"I've got a man here who's traveling around the country on foot, and he'd like to go through the tunnel. I want to give him an escort." It was as if Clark Kent had just turned into Superman. "Call the tunnel authorities and tell them to stop all traffic eastbound when we give the word. I'll cut in on the westbound roadway and hold up that traffic. Make sure those guys in the tunnel turn on the flashers. And let's make it as fast as possible, O.K.? The man's already run 20-some miles today, and I don't want him to cramp up before he makes it through. Let me know as soon as we've got clearance."

A few minutes later I was standing before the tunnel camera and loudspeaker once again. This time, though, the only voice I heard was that of the policeman wishing me good luck.

"Take your time," he said as I broke into a jog. "And have a good trip."

If I'd had any sense I would have followed his advice. Instead, psyched by the flashing lights and the sight of traffic stopped for me, I took off at a fast pace. At the midway point I realized why I'd been going so fast: I had been running downhill.

The second half, of course, was all uphill. As I started up the incline, my thighs and calves tightened. When I tried to compensate by pumping my arms, the only result was that my elbows began banging the backpack. Long before I could even see the end of the tunnel, my lungs and throat were burning from the acrid air—my mouth was like the inside of a tailpipe. If it hadn't been for all the spectators—dozens of Sunday drivers peering at me through their car windows—I'm sure I would have stopped jogging altogether. Not that it would have made much difference: The last few steps were in agonizing slow motion.

When I finally made it to the fresh air, a young guy with a microphone rushed up and started talking about a television station. I was still gasping for breath when I first caught the drift of what he was saying. "...just heard about you on the police radio and we want to tape you for the 10 o'clock news. I'm sorry we didn't have our equipment set up in time to catch you running through the tunnel. When we get the camera and lights turned on, could you do it for us again?"

I probably should have slugged the guy, but for some reason—maybe I was reminded of the policeman's first words or of my shenanigans in front of the security camera—all I did was laugh.

"Sure, I'd be glad to," I said, thinking back to the moment when the soft-spoken policeman reached for his radio. "But you'd have to get the Mobile Police Department to do it again, too. I couldn't do it without them."

Especially not without him—but I didn't do it again.