A 25-year-old Oakland man was killed early Saturday at the MacArthur Maze when the car he was driving slammed into a truck parked in a lane that was closed for repairs, according to the California Highway Patrol. At 2:46 a.m. Gregory Davis Jr. was driving east in a Volvo S80 on Interstate 80 at the maze when he veered into a lane closed to traffic and struck a truck shadowing a crew repairing the guardrail, said California Highway Patrol Officer Sean Wilkenfeld. Before the crash, CHP units on the westbound side of the highway had observed Davis traveling at a speed of 100 miles per hour or more, according to Wilkenfeld, but the crash occurred before a CHP officer could stop him.