Nathan Weitzel, 29, deliberately left two-year-old Isaiah unbuckled before ramming his car into other vehicles at high speed, police said.
Little Isaiah survived but has been left in a body cast with head and neck injuries and a broken leg.
Weitzel, who had two black eyes in his arrest mugshot, allegedly told investigators he took his son to play in a park while thinking of ways to kill him.
He said he then drove around looking for “a good place to crash the car and kill his son”, court papers say.
He had put his own seat belt on but deliberately did not put his son in a child seat and left him unrestrained in the car.
The arrest document says he told investigators “the reason he wanted to kill Isaiah was because being a father was a big responsibility and he did not think he was man enough to raise a child.”
Weitzel was charged with attempted first-degree murder, child abuse, assault and drug possession following the crash in Centennial, near Denver, Colorado, at 11am on August 21.
He was held in the Arapahoe County Jail in lieu of a $500,000 bond.
Isaiah’s mum Nancy Lopez said: “He’s in the place that he should be. He needs to be in jail for a long time.”
She added: “I don’t understand why or how he could do something like this, but I’m hoping Isaiah recovers soon people pray for us and for my son to get better.”
Isaiah is now out of hospital and back at home with his mum Nancy, who has been forced to give up work to look after him.