There was no cannon fired Sunday to start the New York City Marathon, no arterial pulse of runners streaming onto the Verrazano-Narrows Bridge. Instead, geese honked in the desolate silence at Fort Wadsworth on Staten Island. Trees did not come into familiar bloom with leaves of discarded sweatshirts. Empty tents flapped in the wind. Lines of vacant portable toilets stood shoulder to shoulder as if huddled against the cold.

At a BP station where the marathon course turns onto Fourth Avenue in Brooklyn, John San Giorgio, 52, stood with a gas can in his hand. He needed a couple of gallons to get to his engineer’s job at Newark Liberty International Airport. Cars wrapped around the corner. At one point early Sunday, the line stretched for 14 blocks.

“Instead of a marathon course, you’ve got a fuel course,” San Giorgio said.

That was a recurrent scene along the 26.2-mile course, police keeping the peace at gas stations, streets lined not with runners and spectators but with cars stuck in a petrol gridlock. A race in these conditions might have proved upsetting to many. Still, perhaps a few dozen runners started around 9 a.m. and ran through four of the city’s five boroughs, improvising the route as needed, determined that cancellation of the race after Hurricane Sandy would not keep them from completing an unofficial marathon.

Adam Kushner, 49, an architect from Manhattan, started at Mile 4 on the course in Brooklyn, ran back to Mile 2, then did a U-turn and ran to the finish in Central Park, a wrap on his left hamstring.