No person shall turn a vehicle at an intersection unless the vehicle is in proper position upon the roadway as required in § 1160 of the Vehicle and Traffic Law, or turn a vehicle to enter a private road or driveway, or otherwise turn a vehicle from a direct course or move right or left upon a roadway unless and until such movement can be made with reasonable safety. No person shall so turn any vehicle without giving an appropriate signal in the manner hereinafter provided.