What is the test for a right to a speedy trial?

The right to a speedy trial primarily protects three interests of criminal defendants: "(i) to prevent oppressive pretrial incarceration; (ii) to minimize anxiety and concern of the accused; and (iii) to limit the possibility that the defense will be impaired." Barker v. Wingo , 407 U.S. 514, 532, 92 S.Ct. 2182, 33 L.Ed.2d 101 (1972) ; United States v. Ewell , 383 U.S. 116, 120, 86 S.Ct. 773, 15 L.Ed.2d 627 (1966) ("This guarantee is an important safeguard to prevent undue and oppressive incarceration prior to trial, to minimize anxiety and concern accompanying public accusation and to limit the possibilities that long delay will impair the ability of an accused to defend himself."). In addition, the right to a speedy trial serves a societal interest in the fair and efficient operation of the criminal justice system and in limiting the costs to the community of pretrial detention and its deleterious effects. Barker , 407 U.S. at 519-21, 92 S.Ct. 2182.