Following denial of his motion for new trial, X appeals his conviction of driving under the influence of alcohol to the extent that he was a less safe driver. Consistent with Georgia law, the trial court charged the jury that defendant's refusal to permit a chemical analysis of his blood at the time of his arrest gave rise to a rebuttable inference that the test would show the presence of alcohol or some other prohibited substance See O.C.G.A. 40-6-392 (d); Mendoza v. State, 196 Ga. App. 627, 629 (2) (396 S.E.2d 576) (1990). The issues raised by X are whether there is probative evidence that he refused to submit to testing and whether there is sufficient evidence to support the verdict. In evaluating a challenge to the sufficiency of the evidence, we construe the evidence in the light most favorable to uphold the verdict Anderson v. State, 237 Ga. App. 595, 596 (3) (516 S.E.2d 315) (1999). It is a function of the jury and not of the appellate court to weigh conflicting evidence and judge the credibility of witnesses. Porter v. State, 224 Ga. App. 276, 279 (2) (480 S.E.2d 291) (1997). Viewed in accordance with these principles, the evidence shows that at approximately 1:00 a.m. on April 28, 1997, City of Atlanta Police Officer responded to the scene of an accident. Officer observed X standing by an overturned pickup truck. the road was wet due to rain, and X acknowledged that he had been driving the truck. Officer testified that as he spoke with X, he detected a strong odor of alcoholic beverage on X's breath, an odor which pervaded his patrol car after he placed X there. According to Officer, X could not maintain his balance even though he did not appear to be injured or sick. Moreover, his speech was irregular, and his eyes were glassy. Officer testified that X admitted that he had been drinking, but, because of road conditions, no field sobriety evaluations were performed. Instead, Officer gave X implied consent warnings and asked if he would submit to a state-administered blood test. X agreed, and Officer summoned another Officerto transport X to the detention center where the test could be administered. When Officer began testifying as to events that transpired at the center while he was not there, X's hearsay objection was sustained. Officer then testified without objection that after he was summoned to the detention center, he signed a form verifying that X had refused to submit to a blood test. Officer's testimony as to his own conduct and observations authorized the jury to find that X had refused to submit to testing. And the evidence was sufficient for a rational trier of fact to conclude beyond a reasonable doubt that X was guilty of being a less safe driver because he was under the influence of alcohol. Garrett v. State, 230 Ga. App. 97 (2) (495 S.E.2d 579) (1998); compare Groom v. State, 187 Ga. App. 398 (2) (370 S.E.2d 643) (1988).