I don't know Tim! That is just what the book says.
I have watched them clock some about 4 years ago when I went a staff. They were triggering them on the back straight I never saw one do 187 in person, but I saw quite a few over 160. Those speeds don't count for anything anyway. It is the time that counts. I imagine that they are adding a lot of distance. No body rides the rails. It would be impossible to finish this course in 500 meters. I imagine that they are loosing some in the corners, and they are adding about 100 meters running wide.
Hammer