For a second, he hesitated. He had just returned from vacation. "I thought, 'Wow, this is going to pay off my vacation,' " he said. "But it's not my way."
So he called police.
Mike Chitwood, Upper Darby's police superintendent, thought so highly of the decision, he called a news conference Tuesday to trumpet it.
"In this day and age, to turn that kind of cash in -," he said. "Truly, truly a Good Samaritan."
Chitwood said it was unclear where the money came from - though he said no robberies or missing money had been reported.
He wouldn't say if he thought the cash was criminal proceeds. But a five-figure find in the roadway? "It's always suspect," he said.
Across social media Tuesday, few disputed Tracey's Good Samaritan designation.
Some confessed they would have chosen differently.
"Wish I could say I would have done the same . . . there goes a better man!" said one commenter, dubbed Coner, on Philly.com.
"Meet the dumbest man in Delaware County," wrote another on Facebook.
The news led one poster down memory lane. "Y'all remember Joey Coyle???" he wrote.
In 1981, Coyle, an unemployed longshoreman from South Philadelphia, found $1.2 million after it tumbled from an armored car.
Coyle kept the cash - and famously became a local folk hero when he began passing $100 bills around his neighborhood, even to casual acquaintances. He was ultimately arrested, tried, and acquitted. Still, he killed himself in 1993, months before the release of a movie about his life story.
As for Tracey, Chitwood said it's still unclear if he will get a reward for finding and returning the cash.
"In the world of Mike Chitwood, if nobody claims the money, it should go to him," the police superintendent said. "But in the legal world, I don't know."
Chitwood said his office is researching policies surrounding such rewards. A spokeswoman for the Pennsylvania State Police said the agency typically does not allow rewards for money turned into police.
For now, it appears Tracey, who is also a volunteer firefighter for the Springfield Fire Company, may just be running on a little bit of good karma - and widespread praise.
"SEPTA is proud of the actions taken by Mr. Tracey, who is a valued employee with nearly 37 years of service," the agency said Tuesday. Working as yardmaster there, Tracey said, he's had a long history of returning lost items: wallets, keys, and cash that are often left on railway cars.
"I'd want someone to do that for me," Tracey said.
His family, too, was quick to offer words of support.
"That's the man my dad has been his entire life," daughter Sommer Tracey Kelly, 34, said. "We just got back from vacation, and I swear, the man spent so much of his time offering to take pictures for other families."
"If he would have found just $20, he would have tried to find the owner," she said.
At the news conference Tuesday, Tracey said his retirement isn't far off. He glanced at the cash - showcased on the table beside him - and laughed.
"I was $15,000 richer," he said, "for about a half-hour."
Staff writer Jason Laughlin contributed to this article.