Longtime model and television personality Janice Dickinson suffered a head injury in a frightening traffic mishap on a busy Los Angeles freeway. The Web site TMZ.com said Dickinson was a passenger in a car that was sideswiped by a hit-and-run semi-truck on I 405 late Tuesday night, causing her to smack her head into the windshield. Dickinson's publicist said the star of Oxygen's "The Janice Dickinson Modeling Agency" suffered a concussion and was treated at a nearby hospital. No one else was seriously hurt. Dickinson said she'll be ready for the second season of her show, which begins next month.