I. JURISDICTION
This petition for review, filed by the state, challenges the trial court’s dismissal of a driving under the influence of intoxicating liquor (DUI) charge (A.R.S. §§ 28-692(A), 28-692.02) against the defendant, Bert Michael Clewell, and the court of appeal’s failure to accept jurisdiction of the state’s petition for special action. We granted review and have jurisdiction pursuant to Ariz.Const. art. 6, § 5(3) and Rule 8, Arizona Rules of Procedure for Special Actions, 17B A.R.S.
II. ISSUES
We must answer the following questions on appeal:
*303A. Do Rule 8.2(b), Rules of Criminal Procedure, 17 A.R.S., and Hinson v. Coulter, 150 Ariz. 306, 723 P.2d 655 (1986), which require that trial for a defendant in custody be set within 120 days from date of arrest, apply to a DUI defendant who is not in custody pursuant to the current DUI charge, but is in custody on another matter?
B. Did the state exercise due diligence in bringing the defendant to trial?
III. FACTS
Defendant Clewell was arrested on 10 August 1988 for driving while intoxicated (DUI) and for attempting to elude a police officer. A.R.S. §§ 28-622.01, 28-444, 28-445, 13-701, 13-702, 13-801 and 13-812. No DUI charges were filed against the defendant at that time and he was released from custody. He was, however, retained in custody for violating the conditions of his parole in another matter. An indictment and summons for the DUI charges were issued 1 September requiring that defendant appear for arraignment on 16 September. Defendant was still in the custody of the Arizona Department of Corrections (DOC) but did not receive the summons until 13 September. Defendant was released from DOC on 8 December and appeared for arraignment on 16 December. A trial date for 5 January 1989 was proposed, which was 148 days after defendant’s arrest on the DUI charge. Except for a few hours at the time of arrest, defendant was never in custody on the DUI charge, but was in custody for violating the conditions of his parole.
On 23 December defendant filed a motion to dismiss claiming that he was in custody from 10 August to 8 December and that the 120 day time limit for bringing him to trial had expired. The prosecution stated that it was ready for trial within the 150 day time limit for defendants not in custody. The Honorable Patrick O’Neil, Judge Pro Tempore of the Superior Court of Mari-copa County, ruled in favor of defendant’s motion on the grounds that the 120 day “in custody” time limit under Hinson applied, even though defendant was not in custody under the DUI charge.
The state filed a Petition for Special Action and Application for Stay in the Arizona Court of Appeals, Division One. The Court of Appeals declined to accept jurisdiction of the state’s Petition. We granted the state’s Petition for Review because we believe the trial court erred in its interpretation of Hinson.
IV. DISCUSSION
A. Was the Defendant in Custody?
We have held that because of the unique nature of the offense of driving under the influence of intoxicants or with a blood alcohol reading of more than .10 the accused must be tried within 150 days of arrest regardless of whether the offense had been “scratched” or “dismissed” before indictment, information or complaint. Hinson v. Coulter, 150 Ariz. at 311, 723 P.2d at 660.
As we noted in Hinson:
After the police have arrested and removed a drunken driver from the highway as the statute and caselaw contemplates must be done, the prosecutor must proceed to charge or indict as well as try the defendant within the 150 day time limit mandated by Rule 8.2(a) of Rules of Criminal Procedure if not in custody and 120 days from arrest if in custody pursuant to Rule 8.2(b), Ariz.R.Crim.P., 17 A.R.S.. (emphasis added).
150 Ariz. at 311, 723 P.2d at 660.
The state argues that the defendant was in custody only under the unrelated charge of parole violation and, thus, was never in custody pursuant to Hinson. Therefore, the state reasons, the “150 day rule” applies in the defendant’s case.
The defendant argues that the state cannot circumvent the holding in Hinson, by relying on the fact that the defendant’s incarceration was due to a charge unrelated to the DUI charge. We do not agree.
In general, courts do not take into account a defendant’s incarceration for probation or parole violation in calculating the *304speedy trial time period. State v. Dudley, 433 A.2d 711, 713 (Me.1981) (no infringement of speedy trial right where four of the six and one-half month delay was due to incarceration on a probation violation); State v. Smith, 699 P.2d 711 (Utah 1985) (defendant’s speedy trial right did not attach at the time of his incarceration where he was arrested for robbery, but imprisoned for violating the conditions of his parole). See also Mackey v. State, 279 Ark. 307, 651 S.W.2d 82 (1983) (defendant was not denied a speedy trial under the rules where his parole was revoked following his arrest and he was not held in jail solely on the pending charge); State v. Ogden, 21 Wash.App. 44, 584 P.2d 957 (1978) (distinguished between being placed in custody by the court on criminal charges and being detained for parole violation for purposes of 60 and 90 day trial time limit rules).
The Court of Appeals of Washington had occasion to decide whether to apply the 60 day “in custody” rule or the 90 day “not in custody” rule to a defendant arrested on a burglary charge. State v. Christianson, 17 Wash.App. 264, 562 P.2d 671 (1977). The defendant was released on the burglary charge upon his personal recognizance, but remained in custody on a parole violation detainer. The court held that since the defendant was released on the current criminal charge of robbery, but held in custody on violation of parole, the 90 day “not in custody” rule applied. Christianson, 17 Wash.App. at 265, 562 P.2d at 672.
We believe the shorter time limit (120 days) applies only where the defendant is in custody on the current or pending charges relating to the ultimate speedy trial challenge. In the instant case, Defendant Clewell was arrested for DUI but was taken into custody for violating the conditions of his parole.
We hold that when a defendant is arrested and is taken into custody pursuant to a violation of parole and not pursuant to a current charge, such a defendant is not deemed to be “in custody” for purposes of the 120 day trial rule. In such a case, the 150 day rule applies.
B. Due Diligence
The defendant argues that the state was not diligent in bringing the defendant to trial and that the trial court properly made such a finding in dismissing the DUI count. The thrust of defendant’s argument is that during the entire time defendant was in custody under the parole violation, the state knew where to locate him, but did not pursue the matter with due diligence which resulted in prejudicing the defendant. We do not agree.
There are many reasons given for speedy trial rules. One is to ensure that an uncon-victed individual who is ineligible to obtain a pretrial release is subject to minimum pretrial confinement. State v. Royster, 43 Wash.App. 613, 616, 719 P.2d 149, 152 (1986) (citing United States v. Ewell, 383 U.S. 116, 86 S.Ct. 773, 15 L.Ed.2d 627 (1966)). The United States Supreme Court has held:
The Sixth Amendment provides that “[i]n all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial____”
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The Amendment would appear to guarantee to a criminal defendant that the government will move with the dispatch that is appropriate to assure him an early and proper disposition of the charges against him.
United States v. Marion, 404 U.S. 307, 313, 92 S.Ct. 455, 459, 30 L.Ed.2d 468, 474 (1971). The sixth amendment guarantee of a speedy trial 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. Ewell, 383 U.S. at 119, 86 S.Ct. at 776, 15 L.Ed.2d at 630. As we have noted:
The purpose of the speedy trial rule is to insure that a criminal defendant is not forgotten while the orderly administration of justice swirls around him on all sides but leaving him untouched.
State v. Ferguson, 120 Ariz. 345, 347, 586 P.2d 190, 192 (1978). The speedy trial rule *305is simple justice. If a defendant is innocent, that should he determined as soon as possible. If the defendant is guilty, the public should know that as soon as possible. Also, in DUI cases, the defendant can be removed from the streets before he drives again and endangers the safety of others. Furthermore, rehabilitation can be instituted earlier.
Because of the importance of a speedy trial, there is a presumption, especially in a DUI case, that a matter has not been diligently pursued if the time limits of Rule 8 are violated. See State v. Tucker, 133 Ariz. 304, 308, 651 P.2d 359, 363 (1982) (“rule 8 speedy trial right in Arizona is more restrictive of the state than the sixth amendment”); State v. Olson, 146 Ariz. 336, 338, 705 P.2d 1387, 1389 (Ariz.App. 1985). However, the converse is also true. If the matter is brought to trial within the time limits, due diligence is presumed. See Shepherd v. Fahringer, 158 Ariz. 266, 269, 762 P.2d 553, 556 (1988) (as long as the prosecution is ready for trial within the 150-day period, the state should not be penalized); State v. Smith, 146 Ariz. 325, 327, 705 P.2d 1376, 1378 (App.1985) (“When the state is prepared to go to trial within the time limits, we believe it would be inappropriate to require judicial inquiry into whether the defense’s inability to proceed is due to some ‘fault’ on the part of the state.”). In this case, the state was ready to prosecute either 147 or 148 days after defendant’s arrest. There was insufficient evidence of lack of due diligence to overcome the presumption of due diligence. We hold that under the facts in this case, the state was prepared to proceed within the applicable time limit and lack of diligence was not shown.
V. RELIEF
The trial court’s dismissal of the DUI charge is set aside and the matter is remanded for further proceedings consistent with this opinion.
GORDON, C.J., and FELDMAN, V.C.J., concur.