The 24-year-old woman interrogated police and filed motions as she represented herself at trial last year to contest the $100 ticket. She even prepared a list of 96 questions.
She lost, but decided to appeal to the state Supreme Court.
She argued that police failed to respond to her request for engineering studies used to calculate the speed limit on the road where she was ticketed in May 2007 for driving 44 in a 25-mph zone.
On Wednesday, she lost again. The high court concluded that Downs “did not overcome the presumption that the posted speed limit was valid” and that the district court did not err in its finding of her guilt.