Some boys never grow out of their attraction to moving vehicles. As adults, they just transition from toys to the real thing.
So it was for 18-year-old James L. Harris, who was arrested on July 22 in Florida for burglary and grand theft auto of a Miami-Dade Transit bus. According to the Miami-Dade Police Department, Harris dressed up like a bus driver and drove the bus throughout the county.
Darius McCollum, however, is more of a train man. On June 14, the 43-year-old was arrested in New York City for criminal trespassing in the subway. According to the New York County District Attorney's Office, it was his 11th arrest in Manhattan.
McCollum himself counts his total number of arrests as more than 20, all of which were related to his transportation fascination.
Harris' stepmother, Helen, says she is not aware of any medical condition that may be behind his actions, and she refused to comment further on his arrest when contacted by ABC News.
However, McCollum's mother, Elizabeth, says that Darius' train fixation may be related to his Asperger syndrome.
"Asperger syndrome is a close cousin of autism," says Ami Klin, director of the Autism Program at the Yale Child Study Center at Yale University School of Medicine.
This lifelong brain developmental disorder makes it difficult for people to judge others' feelings, thoughts and intentions, Klin says.
In addition, narrow interests are common in people who have Asperger syndrome.
Klin says he has seen patients who have learned everything they can about telephone pole insulators, deep fat fryers, marine biology and currencies. He even maintains a list of 80 or 90 such topics of interest.
"We tend to use our knowledge about people to understand the world of things," Klin says. "With children with autism and Asperger's, they tend to use their knowledge about things to understand people."
Elizabeth McCollum says that her son, Darius, has been in love with locomotives "forever."
"That's my fault," she says. "When he was big enough to barely walk, he was traveling on the train. Every morning we got up and went somewhere. If it wasn't out of town, it was on the subway."
She remembers waiting on the subway platform near their home in Jamaica, Queens, one morning when her son was 4 years old. "He wouldn't let me hold his hand," Elizabeth McCollum says. "He wanted to lean over the track and see the train coming."
When it arrived, she says he pulled her up to the front car and told her to look out the window.
"See! See the tracks!" she remembers him saying. "He knew about tracks, and could tell you about yardage and everything. It's unbelievable. ... He knew that underground system better than he knew his name."
Darius, who now lives with his parents in Winston-Salem, N.C., says that he is fascinated with every aspect of this means of transportation, "the people, the life, the way the train operates, how it all fits together."
By the time he was a teenager, Darius says he talked his way into train yards and employee-only areas of the E and F subway trains, just by saying that one of the workers was his uncle.
"People taught me down there, especially on weekends because there were no big bosses," he says.
He knew so much, he says, that one night when he was 15, a conductor asked him to take over the end of his route. "First I declined, and then said, OK, why not," Darius remembers.