22-year-old Rajesh, son of a realtor, was driving the Audi sports utility vehicle, when it rammed the autorickshaw last night, killing Deepak on the spot and seriously injuring another occupant.
The youth was arrested this morning, Additional Commissioner of Police (Traffic) M A Saleem said.
The accused has been charged under IPC section 304 (culpable homicide not amounting to murder) and was in police custody, he said.
The injured, a colleague and neighbour of Rajesh, had been admitted to a private hospital.
The vehicle belonged to Rajesh's mother, police said.
The deceased was the sole breadwinner of his three-member family and was working in a pub in the city.
