Main Street Vehicle Times

I am in the beginning stages of looking into attempting the Parkeology challenge (All Disney World rides in 1 day). I was looking at a few people that attempted it recently and they were able to ride the Main Street Vehicles at 8:00am but the Magic Kingdom did not open until 9:00am on that day. When I look at the upcoming hours on the Disney website all of the times correlate that the Main Street Vehicles have their start at park opening. Do the vehicles regularly run before park open when Main St is open before the rest of the park opens?