A man accused of killing three family members and kidnapping his young son in Georgia surrendered to the police on Wednesday night after an armed standoff that snarled traffic for several hours on a Florida highway, the authorities said.

The man, Caesar Zamien Lamar Crockett Jr., had put a gun to his head inside his car after it crashed following a high-speed chase with the police, the authorities said. Mr. Crockett had quickly handed over his 2-year-old son to officers but then barricaded himself inside and refused to leave.

Chief Brian Dugan of the Tampa Police Department credited the “peaceful resolution” of the standoff to the many officers who responded and to the negotiators who persuaded Mr. Crockett to surrender.

“They just kept talking to him,” Chief Dugan said at a news conference on the exit ramp off Interstate 4, where Mr. Crockett had holed up inside his car. “I don’t know if he got tired or what, but he eventually surrendered and we were able to take him into custody with no problems whatsoever.”