The question was what is a profilograph and how is it used? I tried to explain the use of one on a drag strip in order for a grinding company to know where to grind. The same process is used in most states after the pavement is laid to meet whatever specs that state has as to the flatness required for final inspection to be approved. A profilograph isn't used on a race track for the benefit necessarily for the competitors,but for the grinding contractor to enable them to know what area needs to be ground.As far as how crew chiefs adjust to bumps and dips they will have to explain that. I can only discuss the why to profile not how to adapt it to making a good run .