Few sure things exist in the sporting world, but a traffic mess is guaranteed Thursday when the 49ers play a home game at Levi’s Stadium in Santa Clara during the height of the evening commute. Kickoff for the nationally televised “Thursday Night Football” game is at 5:25 p.m., meaning anyone driving to the game against the Los Angeles Rams might want to start heading for the stadium around lunchtime. Traffic throughout the South Bay starts to tie up on an average weekday, game or not, around 2 p.m.