2009.52: Infallible Sobriety Test Works for Alcohol and All Drugs
Unfortunately, this test in not very portable, but it could be installed at all police stations, in minivans or possibly the back seat of patrol cars.
The principle is simple: the testee is asked to thread a 16mm movie projector. Since these are becoming hard to find, I suggest that certain Grundig reel-to-reel tape recorders might also work.
