A Bronx driver plowed into a 16-year-old boy — leaving him clinging to life — and then struck a parked NYPD vehicle as he tried to flee, cops said. 

The 21-year-old motorist was driving a 2011 Nissan Altima south on Webster Avenue near East Gun Hill Road in Norwood just after 9 p.m. Tuesday when he crossed over the double yellow lines into the opposite lane, striking the teen cyclist heading north on Webster, authorities said. 

The teen was thrown from his mountain bike and taken to Jacobi Medical Center in critical condition. 

The driver tried to flee from the scene — but ended up backing into a parked, unoccupied police car, authorities said. 

He was taken into custody with charges pending, and brought to Jacobi to be treated for minor injuries, cops said.