An eighteen-wheeler sat motionless at the intersection of 26th Street and Fourth Avenue in Brooklyn, completely blocking traffic in all directions. As motorists blasted their horns in an orchestra of rage, the bewildered truck driver hopped down from the cab and began yelling — in a distinctly out-of-town drawl — at the pileup of cars behind him on 26th, demanding they back the heck up.

It was a fairly routine roadway scene on a typical Wednesday afternoon in October, along the course of one of the most famous foot races in the world.

The New York City Marathon, a challenging 26.2-mile foot race that snakes across the city on the first Sunday in November each year, is the stage for some of the most remarkable athletes in the world. The best of them practically sprint from Staten Island to Central Park, traversing neighborhoods, bridges, boroughs and millions of spectators in a little over two hours.

It is generally considered the largest marathon in the world, with almost 48,000 contestants last year. But they had no lost trucks to contend with, no red lights, yellow taxis or blue buses. On race day, like this Sunday, the course is cleared of traffic. But imagine running it on a Wednesday afternoon.

We thought of something even more absurd.

We set out on a semi-scientific quest to determine whether a car can drive the New York City Marathon course — smack in the middle of weekday afternoon traffic — in less time than an elite racer runs the actual circuit. We had a full tank of gas, thousands of dollars in camera equipment, a water bottle and a pioneer’s curiosity.

We discovered so much more. We saw a changing landscape as we slalomed through some of the world’s most notorious urban snarl. We met fascinating people and treated ourselves to some of the best comestibles in the city. Most of all, we did what very few people ever do when not running a marathon — or for mayor. We touched all five boroughs in the same day.

I was behind the wheel of a gray 2021 Subaru Impreza, and Jonah Markowitz handled the cameras, producing a glowing portrait of one extended corridor of a magnificent metropolis.

Our “carathon” — something between a grand prix and a day of errands — began at the race’s starting point on the Verrazzano-Narrows Bridge on Wednesday, Oct. 4, at precisely 1:56 p.m. The grueling event tested the very limits of our endurance and our ability to withstand hours of New York City traffic with only one bathroom break.

We followed the same route as the runners except for tiny adjustments to maneuver around one-way streets and the fact that, thankfully, cars are generally not allowed in Central Park. We synchronized our stopwatches and employed the following rule: Any time we stopped for logistical reasons — to change the camera mounts or interview residents — we paused the drive clock. But just like the runners, if we pulled over for a quick refreshment or used a rest room, the drive clock ticked on.

After we squeezed past the stalled tractor-trailer, we approached Atlantic Avenue and came upon a gleaming micro-neighborhood of stout apartment buildings — on the line between Park Slope and Boerum Hill — that barely existed a couple of decades ago.

I once attempted a vaguely similar drive back then — though not nearly as precise — and some neighborhoods along the route were vastly different now. Williamsburg had few of the trendy restaurants and bars. Long Island City had only a fraction of the steel and glass, and in the 1990s there was nothing resembling today’s fleet of delivery vans and bikes. Some of the graffiti seemed familiar.

Our pace was already well behind that of an elite marathoner, whose average speed of almost 12 miles per hour is the stuff taxi drivers dream of. Around 3:30 p.m., we turned onto Lafayette Avenue and met Kaya Nico who has lived near there most of her life. She described marathon day festivities in front of her house over the last 23 years. For several years, Ms. Nico and members of her band, the Skins, set up on the sidewalk and played for the runners.

“They keep coming all day,” she said. “It’s like you’re playing for 50,000 people.”

Another neighbor, Mr. Meyer, who declined to give his first name, said the marathon is fun but also an incredible inconvenience.

“You can’t get around it,” he said. “It’s like they split the city in two and there is a big border in between. It’s suddenly like it’s two countries.”

Before long, things grew hectic. In Greenpoint, when we were taking a corner on Manhattan Avenue, a mounted camera flew off the car and landed in the intersection. Careening to a halt, we leaped out to rescue the equipment before it was pulverized. We seized the opportunity for a restroom break in a most hospitable establishment called Bar Bruno.

Still shaken from the camera incident, we required sustenance. Like marathoners reaching for a cup of water, we entered the Peter Pan bakery, a period-piece diner on Manhattan Avenue with a reputation that dates back to the 1950s.

Francine Nunez, the manager and sister of the owner, has been working at Peter Pan for almost 25 years and said that on marathon days, workers hand out munchkins to runners. We bought two whole doughnuts, including the gorgeous vanilla cream, and devoured them.

We crossed the halfway point of the race — the new Pulaski Bridge — and landed in Queens at 4:40 p.m., passing through a shiny part of Long Island City that runners from previous decades would hardly recognize. But fans of “Taxi,” the 1970s television show, would definitely recognize the breathtaking views of Manhattan as we crept onto the 114-year-old, double-decked, cantilevered Ed Koch Queensboro Bridge.

On the other side of the East River, the late-afternoon sun reflected off some of the most iconic edifices on earth — the Empire State and Chrysler buildings — and the imposing Citicorp, all aglow in a gloss of orange.

Manhattan was under our tires at 5:22 p.m. On marathon days, spectators on First Avenue provide rousing support for the runners. We didn’t hear a clap. Undaunted, we continued on to East Harlem and pulled over at Patsy’s Pizza at 118th Street for the best slice in the city (not even a debate).

The course only clips the mainland United States in a one-mile turn through the South Bronx, another area along the route where new apartment buildings have spouted in recent years.

To many runners on race days, this is where spectator support wanes. But Rashauna Richardson, a school administrator who lives on 138th Street, told us the marathon still has an impact there.

“Traffic is brutal, parking is brutal,” she said of marathon days. “Not too many people in this community are big fans of the marathon. Not too many attend. People here like the more popular sports.”

Over the Madison Avenue Bridge and back to Manhattan. Runners find this part of the course tricky, with 22 miles behind them but a notable incline up Fifth Avenue. In a car, it wasn’t hard at all.

We passed the statue of the great Duke Ellington, and at 6:34 p.m. the Metropolitan Museum of Art came into view. A four-hour finish was within reach. Unable to swerve into the Park at 91st Street like the runners do, we continued down Fifth Avenue, hitting 60th Street at the 3:21 mark.

At 7 p.m., after sunset, we passed horse-drawn carriages and Hare Krishnas chanting at Columbus Circle. With a last-minute surge fueled, no doubt, by the delectable doughnuts and pizza, we whisked up Central Park West and into a garage on 66th St.

From there, we scampered into the welcoming park on foot and reached the finish-line plaque near Tavern On the Green in exactly 3:51:02 of drive time. It was 7:34 p.m. — five hours and 38 minutes of real time had passed since Staten Island.

We found Matt Chisholm, a health care administrator, jogging by. He has run several marathons, completing one in 3 hours, 58 minutes, and he said he felt the physical toll for days.

“It doesn’t matter how you do it,” he said. “Just finishing is an achievement.”

He wasn’t referring to us. Then again, we weren’t sore the next day.