A curve's posted design speed is: Question A curve's posted design speed is: Answers Safe for buses. Safe for all vehicles, including buses. The minimum speed at which the curve should be driven. Not always safe for buses. Explanation Even under ideal weather conditions, a bus being driven at the posted design speed for a curve could either roll over or slide off the road. For safety, you should reduce your speed before driving a bus around a curve. This questions appears in the following tests: Georgia Passenger New Hampshire Passenger New Jersey Passenger Pennsylvania Passenger South Dakota Passenger