Video captured by a family driving on a highway in Boston, Mass., shows the moment a person behind the wheel of a black Lexus started "driving erratically," before almost hitting a pedestrian on July 23.

Charles Atherton, whose son recorded the video, said he spotted the SUV swiping the guardrail twice and crashing into another vehicle near Dorchester, a neighbourhood in Boston.

The SUV then flipped into the intersection, narrowly missing a pedestrian who was waiting on the side of the road.

After the narrow miss, the pedestrian then "helped pull the 24-year-old driver to safety," Atherton told Storyful.

Local news reports suggest a total of five vehicles were involved in the crash, while "the driver was transported to the hospital with non-life-threatening injuries."

With files from Storyful