The 43-year-old was travelling along Greens Way, Mexborough, when his Vauxhall Zafira left the road and crashed into railings.
He was taken to hospital with life threatening injuries.
His passenger, a 46-year-old woman, escaped with minor injuries.
Police officers investigating the collision, at 10.50pm on Saturday, want to hear from witnesses.
Anyone with information should call South Yorkshire Police on 101.
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