Here is a video of the start of last years race:
Radio operators are stationed at each checkpoint where the bikers have to stop for a split second while their bikes get marked with the checkpoints color so they can track if you cheated or not at the end of the race. There is also gas and water at the checkpoints if the bikes and riders need it.
We also have radio operators with the medical unit and the helicopter that flies the route.
It's one of the events I look forward to each year.