One of the last vestiges of the “old” Daytona International Speedway came crashing down in the teeth of a steel-toothed excavator Thursday morning.The Speedway’s 57-foot welcome sign on International Speedway Boulevard was quickly removed by a crew from Barton Malow, the primary contractor for the $400 million Daytona Rising, which will be complete in January.Speedway vice president of operations Andrew Gurtis was overseeing the demolition.“We unveiled this sign just before Speedweeks in 1994,” Gurtis said.