Supreme Court of Tennessee Blog, By Daniel Horwitz -
Tennessee drivers beware: stray outside your lane – even an inch, and even for just a moment – and you’re subject to being seized and arrested by law enforcement. Also, you’ve just committed a crime that can land you in jail for up to a month.
In a pair of companion cases handed down by the Tennessee Supreme Court on Thursday afternoon, the Court observes that “[o]ur legislature has chosen to criminalize the common driving infraction” of crossing lane lines. Moreover, the Court explains, the fact that “drivers in Tennessee  cross lane lines ‘all the time’” makes no difference. No matter how minor the offense, if you’re suspected of having committed any driving infraction of any kind anywhere in the state, then neither the Fourth Amendment nor the Tennessee Constitution will protect you.
...it is now a fact of life that virtually any driver in Tennessee can be stopped and jailed anywhere and at any time simply on an officer’s whim for no reason other than that it is impossible to drive perfectly within one’s lane at all times.(link)