After testing for smoothness and rideability in the base level using a profilograph test, the laying of the surface track has begun. Tests will continue as the project moves forward with next steps including, new curbing, creating a gravel pit, fence restoration, and more.
South State is using their milling machine set at 0-inch mill depth to just remove any of the high points, or bumps, that the surface may contain. This will allow for the smoothest surface possible prior to placing the wearing course. We are looking for a profile index (PI) of around 10 in/mile. The reported data for the base course was already very good as is, especially for being placed on existing aggregate base. Each successive lift improves the smoothness between 50 – 70 percent!
Next, portions of the curbing will be removed and renovated. The profile of Turn 1 will be altered slightly with the apex curbing placed further inside, taking advantage of the unused space and pavement at that point of the turn.
The asphalt and concrete work will be completed by Thanksgiving. The new track base and surface will be allowed to cure from December through February.
The final touches and line painting will be done late in February, and Thunderbolt will reopen for normal business operations in early March, 2024.
Phase 2 – the addition of two new alternative course configurations inside the classic Thunderbolt circuit – has been rescheduled for after the 2024 season.
