here is from the news.

Sikes called 911 on his cell phone. He reached a trainee dispatcher, who alerted nearby CHP patrol officers and suggested a number of ways to slow down the car. Sikes said none of them worked.

CHP Officer Todd Niebert caught up with Sikes and used the loudspeaker on his CHP cruiser to coach Sikes. Niebert offered a number of suggestions but said none of them worked. The Prius reached a top speed of 94 mph as Sikes dodged slower cars and semi trucks for about 30 miles.

Niebert said he finally suggested that Sikes press the break pedal and the emergency break at the same time as the car climbed a moderate grade.