The driver in this case, Alyssa Villanueva, is facing charges of murder, drunk driving, and felony hit and run.
24-year-old Regan Johnson was adjusting some cones on northbound 99, when a silver Nissan sped through a lane that had been closed for construction.
She worked for a construction company, but was not a CalTrans employee.
The vehicle was spotted in the construction zone as far south as 99 and Olive.
Sgt. Gil Piersol, CHP: "Someone with total disregard for everybody's safety crossed into the closure itself and was traveling at an excessive speed."
CHP says the driver, 26-year-old Alyssa Villanueva, hit Johnson near the Clinton exit and kept going.
She died at the scene.
Two CHP units were on scene at the time of the collision, but the vehicle wasn't located until later in the morning, at an apartment complex on west Ashlan.
An anonymous tip to Fresno police led officers to the Arbor Ridge apartments.
Officers went to the complex, and arrested Villanueva. And her step-father, Antonio Rios, Jr.
CHP says rios covered up the car with a tarp, after Villanueva called him following the collision.
Sean Duncan, CHP: "It's absolutely absurd. Ridiculous, in my opinion, for this person to go into a construction zone, into a lane closure and drive at speed just because they want to pass the vehicles in the open lane."
Johnson's friends say she had been studying at Fresno State to become a teacher.
CalTrans says her death is a lesson to us all about the dangers construction workers face while working on our highways.
Officials say to slow it down to 45 miles per hour.
Jose Camarena, CalTrans: "This is another example of what can happen, what does happen, and why we need the public to slow down for these cone zones."
Again, Alyssa Villanueva is facing charges of murder, drunk driving, and felony hit and run.
Her step-father, Antonio Rios, Jr. is facing charges of obstruction.
CalTrans is urging drivers to be cautious on Highway 99 this summer.
There are currently 10 projects going on along the Fresno corridor of 99, and dozens throughout the state.