The L is the best mass transit system in the United States. Not the fastest, nor the most reliable. Not the newest, nor the longest. The best. Yes, it has its drawbacks. It’s undeniably loud, and a quarter of the year, you freeze your ass off waiting on cement platforms 30 to 40 feet above the street, where the wind is cruelly pronounced. Even so, the L is the best because of where you are when you ride much of it. Elevated. So much can be seen. The L reveals a Chicago of a thousand unconsidered angles, offers a view without filter or comparison.

So this winter I rode the L—the whole thing, in one day—to see what I could see. To take the measure of a city in full.

I got on the Red Line at 6:32 a.m. at Grand, rode north to Howard, changed to the Yellow to Dempster-Skokie, returned to Howard, took the Purple to Linden in Wilmette, turned around and rode to Clark/Lake, transferred to the Orange to Midway, returned, rode around the Loop, got off at Roosevelt, took the Green south to Ashland/63rd, then backtracked to Garfield, where I took the Green’s other branch, south again, to Cottage Grove. I returned to the Loop, got off, walked back to Grand, and rode the Red down to 95th/Dan Ryan. It was 1:00 when I got back to the Loop. I got on the Blue, went to O’Hare and back, continued all the way out to Forest Park, backtracked to Clark/Lake, picked up the Pink west to 54th/Cermak in Cicero, then returned to the Loop. From there, with the afternoon going kaput, I rode the Green out to Harlem/Lake in Oak Park and back, then headed north on the Brown to Kimball to seal the deal. By then it was 6:28 p.m.

All the while, I took notes.

Early morning, much of the activity on the L is about the body. A lot of sleeping. A fair amount of hydrating. Throat clearing. Yoga stretching. Knuckle cracking. Some furtive nose picking. Fingernail clipping. Lipstick. Visine. Tums. ChapStick. A lot of ChapStick is applied on the L.

At Belmont, cold be damned, the doors are held open way too long. Minutes. Many of them. Car sounds, icy wind, WTF.

There’s not a lot of talking on the L. It’s too loud. And there’s always something to look at out the windows. This does not make it a particularly unfriendly place. Once I was asked for directions. Twice for spare change. One woman asked if it was all right to bless me. (It was.) Two people liked my jacket. One liked my hat. Beyond that, only four people spoke to me in 12 hours.

“That’s a red-tailed hawk,” said one guy on the way up to Skokie. He sat down next to me, way too close, really, extended his arm, and pointed—to a tree or a phone line, I cannot say. He smelled like sandwich meat. I couldn’t claim that I saw the bird. Wanted to. Didn’t. I shook my head at the gray morning shooting by. The bird watcher kept on. “A red-tailed hawk is a supreme predator,” he said. “They eat the rats. That’s why Chicago has no rats.”

I tried not to turn to him. Fear the capicola. “Is that true?” I asked no one in particular. “No rats in Chicago?”

“Very few,” he told me. “Very, very few rats.”

The woman across from us shook her head. “I see rats every day,” she said. “Look out the train window in the morning? You see rats.”

“Very, very few,” the bird watcher said. “Manila has 30 times the rats that Chicago does.”

“Manila?”

“Yes. In the Philippines.”

The woman stood. She’d reached her station. Or maybe she’d just had enough. “We better send them some of them hawks then,” she said as she left.

Young men seem to feel comfortable traveling in pajama pants with no underwear.

Old men seem unaware that their pants can split in the crotch.

The city changes more rapidly in tone and timbre than you could ever imagine. Tunnels of trees flare away from the tracks. Gardens fill the yards. And then, suddenly, block after block sits in rubble, not a tree in that world. What is this place? you want to ask, but exactly no one else is riding in the car with you then. What disaster was this? But before you can name it, you are gone and soon thatcheting along, atop a neighborhood where children on bikes own the streets and shop windows cast warm circles of light on the boulevard.

Best take on the downtown skyline: the Pink Line. Between Ashland and 18th. A CTA employee ending his shift told me the optimum time is at dawn, with the sun pinching through the valleys of the buildings.

The split between the North and South Sides is evident in the geography of the L. The North Side ride is all about proximity. The train slices close to apartments, back porches, offices, conference rooms. You can see into windows every now and then. I could recognize the cereal boxes in one kitchen. A man cooking eggs in another. Nothing lurid. From the train, you only get a moment to regard each window. Dry cleaning, posters, ancient bedsheets—all of it hung in compensation for the proximity of the tracks. People living near the L don’t want to wave every time it goes by. They want to block it out.

What you see becomes part of the rhythm of what you hear. One image cranked up against the next, an inventory rattled together by the sound of the train. Fire escape. Fire escape. Satellite dish. Back porch. Gate door. Shed. Soffit. Scaffold. Dryer vent. Dryer vent. Pipe. Transformer. AC. Dish. Fire escape. Dish.

The South Side is about distance. The trains veer high above empty spaces, vacant lots, along the highway, through parking areas, abandoned construction sites. Your gaze falls higher. Above and beyond. You grab on to the skyline when you can.

People find ways to pass the time. I saw one active crossword puzzle. One woman writing thank-you notes. About 40 newspapers. Eleven magazines. A man playing with Silly Putty. College students watching a movie on an iPad. Lots of headphones. Lots of phone games.

People text, of course. And people read texts over the shoulder of others. Privacy is relative on the L. It is easily possible to read entire text exchanges. I saw the following while standing over a young Asian student on the Brown Line.

Wahtja tell him?

Not to come.

What wus excuse?

Marta dinnit want him there.

What he say

Said some shit about his sister always telling him

Whut?

She warned him about M.

I kno

Did you pickup the parakeet yet?

I forgot it yesterday.

I know. Right.

Someone on these trains is dropping a lot of change. I picked up a total of $1.87, one or two coins at a time.

Women are besieged by men. One guy looking at porn on his phone flashed the screen to a lady, a complete stranger, standing next to him. Another sat, with a young woman to his left, seemingly absorbed by the task of softly reading back the contents of his sexts aloud, as if checking the grammar and style before sending them. “I want to put my nose into you,” he whispered. Then he did a different read-back. “Up into you?” With that, the woman next to him sighed and rose to her feet. She crossed the aisle and sat down heavily. The sexter pretended he didn’t notice, continuing to stare at the ceiling for answers.

People still read books. I spotted 16 hardcovers, nine paperbacks. Only one of them was a Harry Potter book.

Every station reads like the set of a different movie. Dempster-Skokie evokes the classic small-town train station. Passengers approach on foot. Christmas music echoes on tinny speakers. Nurses gather in any available windbreak to share a cigarette. Men eat unadorned doughnuts and read newspapers they carry neatly folded under their arm, scanning the far track every so often for the incoming train, as if they were reliably performing a service for the group.

Clark/Lake hangs like a bird’s nest above the jammed street. An urban mise en scène peopled by students, cops, doormen, car rental agents, lawyers, clerks, cooks, cyclists, French tourists, German tourists, Danes, families laden with rattling shopping bags, cabbies coming off shift. This is where stories begin.

The 95th/Dan Ryan station feels like an absolute end, a harshly indifferent space at the southern terminus of the Red Line, drawn from a dank, dark science-fiction movie. The ocean of cement, the chainlink fence, the bull rush of traffic clatter. It’s the end of the line in every detail.

Best sprawling view: the Orange Line. Heading out of the Loop, where the track rises sharply above deserted rail yards and swings southwest, leaving the city naked and new in front of you.

No one smokes. Not even a vape. Not even a toke. We have come this far.

The Red Line’s south end has its own ecosystem. Past about Cermak-Chinatown, it gradually becomes a kind of marketplace. Old men sell chocolate bars. Energy drinks. Loose cigarettes. Lighters. Tube socks. Younger men walk the length of the car clapping and uttering a word or two over and over again. I couldn’t quite catch it because they didn’t say it in the direction of the bearded old white guy who might well be a cop. They are selling weed in unbearably small Ziploc bags. The energy drink guy also ignored me.

Retailers wander up and down the train. None of this activity is any bother at all. They ask only once and move straight through the car without hassle. I bought one cigarette (tossed it, menthol) and one pair of socks.

“Nothing better than socks on a cold day,” an old man told me when he pulled out the pair.

“I think there might be,” I said. “I think gloves might be better.”

“And soup is good too!” the woman across the aisle told him, her arms folded across her chest. She seemed to know him. “Go get you some soup.”

He pulled his chin in and hissed at her. “Soup, shit,” he said. He wanted me to buy a second pair. “Man, those socks are mittens right there,” he said. “Put ’em on your hands. Then you buy more socks for your feet.”

I allowed that as a possibility, then asked if he was selling any drinks. He’d just opened a soda, as it turned out. “You can have it,” he said, taking a can from his jacket pocket. “It’s a Tab. I don’t like Tab.”

I do. But I passed.

“I haven’t had none,” he said. “I didn’t drink any.” He showed me the can’s top. It was dusty, with no sign of lip marks. It did look full. Still, I shook my head.

“Then why did you open it?” the woman asked him. “You didn’t want a drink? You just opened it?”

He turned to her and stamped a foot. “Charlotte, why you doing me like that?”

“Why you selling opened-up soda pop, baby boy?” she said levelly.

He grimaced. Then moved on. I shrugged when Charlotte looked at me. “He just crazy,” she muttered to herself, breaking off eye contact by closing hers.

We gave in to the ride.

Best ride: the Brown Line. Because it’s short. Because it runs through neighborhoods. Because it is jammed with people who smell good. Pretty girls trundle on and off, often riding a mere station or two.

It’s certainly no record. I’m no iron man. There is no medal for slouching toward Kimball.

I ate nothing during my 12-hour ride, drank two bottles of water, read four pages of a book, took one page of dense notes, sketched a picture of my wife, listened to one playlist, put on my new socks, and walked the length of every platform on which I stood. The experience was muscular, taxing. Traversing a city always is.

The river, the lake, the skyline, the streetlights, the side streets, the rooftops, the houses, the condos, the gardens, the storefronts, the malls, the footpaths, the highways. Banal, familiar. Peculiar, particular. Chicago: heart and fringe. I did it in a day. With a $10 pass. Plus a buck for socks.