What is the purpose of rumble strips on the roadway?

Answer: C — To prevent drowsy or inattentive drivers from leaving the roadway

Rumble strips are designed to create a loud noise and vibration when driven over, which serves as an alert to drivers that they are leaving their lane. This is especially helpful for preventing accidents caused by drowsy or inattentive driving, as it jolts the driver's attention back to the road. Option A and D are incorrect because rumble strips are not located near toll booths or parking areas, but rather on the edge of the roadway. Option B is incorrect because while rumble strips may help guide drivers at night by providing tactile feedback, their primary purpose is for safety purposes as described in option C.