What is the test for determining whether a driver was driving under the influence of alcohol?

be established by circumstantial evidence which, in this case, includes appellant's objective physical symptoms and refusal to submit to chemical testing under California's implied consent law. (CALJIC 16.835.) The prosecution was not required to prove any specific degree of intoxication. (People v. Crane (2006) 142 Cal.App.4th 425, 432.)

Appellant asserts there is no empirical evidence that his alcohol consumption impaired his ability to drive safely but the evidence clearly shows that appellant was under the influence and drove recklessly. (See People v. Weathington (1991) 231 Cal.App.3d 69, 84 [manner of driving can be considered in determining whether defendant was DUI]; McDonald v. Dept. of Motor Vehicles (2000) 77 Cal.App.4th 677, 686, 688 [Vehicle Code section 23152's "'under the influence'" means alcohol impaired driver's mental and physical abilities to such a degree that driver no longer has the ability to drive a vehicle with the caution characteristic of a sober person of ordinary prudence under the same or similar circumstances].)