Adam Bolton, 22, of Almond Avenue, Cudworth, was the passenger in a car which was travelling down Littleworth Lane at teatime on Monday when it struck the chicane.
Adam, and the driver were thrown from the car, and both suffered spinal injuries.
Adam’s uncle, Roy Gleadall, 42, of Prospect Street, Cudworth, claimed the car hit a newly laid section of the pavement which juts out into the road in an unlit area which there were no warnings about.
He said: “For last 30 or 40 years it has always been a straight road, but they’ve put this section in and I’ve seen people struggling to get by.
“It’s pitch black down there at night, there are no warnings or signs to say the road has been changed.
“They’ve come down Littleworth Lane, thinking it was a straight road, hit this curb that’s been built on and ended up rolling the car.
“I think it’s a traffic calming measure, but it doesn’t need to be there. It was an accident waiting to happen.
“If you haven’t been down there in the last few weeks, you wouldn’t know it was there.
“Nobody has died, which is good, but other drivers need warning about it.”
Police are appealing for information about the crash, anyone who can help should call 101 quoting incident number 764 of November 13.