An 83-year-old pedestrian was seriously injured in an accident with a car in Stevenage on Tuesday night.
A Hertfordshire Police spokesman said the woman, who has not been named, was out walking her dog when the accident happened as she crossed Grace Way from Almonds Lane at about 1845 GMT.
The car was a Vauxhall Nova driven by a 29-year-old Stevenage man.
The woman was taken to the Lister Hospital with serious head injuries and multiple fractures.
She was later transferred to the Middlesex Hospital in London where her condition is described as serious.
Her dog was killed in the accident.