§ 3334. Turning movements and required signals.
(a) General rule.--Upon a roadway no person shall turn a vehicle or move from one traffic lane to another or enter the traffic stream from a parked position unless and until the movement can be made with reasonable safety nor without giving an appropriate signal in the manner provided in this section.
(b) Signals on turning and starting.--At speeds of less than 35 miles per hour, an appropriate signal of intention to turn right or left shall be given continuously during not less than the last 100 feet traveled by the vehicle before turning. The signal shall be given during not less than the last 300 feet at speeds in excess of 35 miles per hour. The signal shall also be given prior to entry of the vehicle into the traffic stream from a parked position.
(c) Limitations on use of certain signals.--The signals required on vehicles by section 3335(b) (relating to signals by hand and arm or signal lamps) shall not be flashed on one side only on a disabled vehicle, flashed as a courtesy or "do pass" signal to operators of other vehicles approaching from the rear, nor be flashed on one side only of a parked vehicle except as may be necessary for compliance with this section.
(d) Discontinuing turn signals.--Turn signals shall be discontinued immediately after completing the turn or movement from one traffic lane to another traffic lane.