Rocco Scuiletti was charged Wednesday with leaving the scene of the Friday crash just south of Exit 4 on Interstate 684, The (White Plains) Journal News reported.
Police said Scuiletti was driving a tractor-trailer when he was hit by Kennedy Friday morning.
Despite knowing his truck had been hit, Scuiletti left the scene without reporting the crash to authorities, police said.
Kennedy, the daughter of former U.S. Sen. and Attorney General Robert F. Kennedy, was charged with driving while her ability was impaired by drugs.
Witnesses who called police to the scene said Kennedy was driving erratically before striking Scuiletti. She also failed a field sobriety test, officials said.
She has pleaded not guilty to the misdemeanor charge.