Betty Burden was pulled over in March after dropping off students and heading to the school district's bus garage.
But Burden's attorney says she was not driving erratically and she did not appear to be intoxicated.
Police say they acted on a call from the former district's transportation coordinator who said Burden smelled of alcohol.
Burden admitted to drinking vodka and tonic earlier in the day.
The judge did not rule on Friday's motion.
