I'm making an addon for Lapper to simulate a safety car, as there is no way to launch a safety car from a dedicated server.
Basically, when a safety car is called by an admin, the race will go full course yellow, indicated by a flag in the centre of the display. The drivers will then need to slow down to a maximum of 120km/h, and if they ovrtake, there will be messages on the screen telling them to get back in order (drop X places). They will also get messages to slow donw/speed up depending on the gap between the next racer in line.
Then when it restart time, they will be green lighted as they cross the start/finish.