"Alcohol reduces driving ability, don't drink and drive." to run in a different vein.
What if that was the warning - Text box at top or bottom.
The barcode lines are vertical, but you get the impression you are looking over the steering wheel and the lines project ahead and then get either blurry or distorted or there is an approaching car/truck/bicycle/person?
http://www.armcosignage.co.za/i/W-Symbolic_Signs.pdfparticularly like w333