Delaware Code Title 21. Motor Vehicles § 4155. Turning movements and required signals

(a) No person shall turn a vehicle at an intersection unless the vehicle is in proper position upon the roadway as required in § 4152 of this title, 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 or turn so as to proceed in an opposite direction unless and until such movement can be made with safety without interfering with other traffic.  No person shall so turn any vehicle without giving an appropriate signal in the manner hereinafter provided.

(b) A signal of intention to turn or move right or left when required shall be given continuously during not less than the last 300 feet or more than 1/2 mile traveled by the vehicle before turning.

(c) No person shall stop or suddenly decrease the speed of a vehicle without first giving an appropriate signal in the manner provided herein to the driver of any vehicle immediately to the rear when there is opportunity to give such signal.

(d) The signals provided for in § 4156 of this title shall be used to indicate an intention to turn, change lanes or start from a parked position and shall not be flashed on 1 side only on a parked or disabled vehicle, or flashed as a courtesy or “do pass” signal to operators of other vehicles approaching from the rear.