In researching a Tennessee law related to a client's recent DUI stop, I came across the Tennessee Court of Criminal Appeals 2000 decision in State v. Gonzalez. In such case, a Franklin, Tennessee (Williamson County) police officer initiated a traffic stop of a vehicle after it failed to use its turn signal.
The court reviewed Tennessee law and particulary the code sections related to turning movements (T.C.A. 55-8-142) and signals for turns (T.C.A. 55-8-143) and concluded that a turn signal is only required when another vehicle may be affected by the turn. In the Gonzalez case, the testimony was that there was no traffic directly around the turning vehicle. The officer also admitted that he was not affected by the turn. Since the turn did not affect others, the court concluded that a traffic violation did not occur and thus found the stop was unjustified. By invalidating the stop, the court reversed the defendant's conviction for simple possession of cocaine.