My doctoral advisor confessed to me on the day of his retirement (same as my graduation) that he almost didn't get the job he was now retiring from because he had been ticketed by campus police (during his own doctoral work) for riding his bike on campus while drunk.
I've seen a few steel frames with creased downtubes that never, ever saw a garage door. Curbs can be deadly to drunks.
My point was more to the subtle difference between a uni and a bike - you can't ride it unless you constantly pressure split between *both* feet - if you can ride an unelectrified uni drunk you won't fail the heel/toe test. So speech and other motion control (spastic arms say) is likely to be more telling.