Interesting Case Striking Down a Traffic Law as Unconstitutionally Ambiguous

It's a 2009 case, McNair v. State (Ga.), but I just came across it. Georgia law provided:

The driver of a vehicle intending to turn left shall approach the turn in the extreme left-hand lane lawfully available to traffic moving in the direction of travel of such vehicle. Whenever practicable, the left turn shall be made to the left of the center of the intersection and so as to leave the intersection or other location in the extreme left-hand lane lawfully available to traffic moving in the same direction as such vehicle on the roadway being entered.

Do you see the ambiguity?

If only English had parentheses like computer languages or algebra! There are two ways of parsing the second sentence:

1. "Whenever practicable, the left turn shall be made to the left of the center of the intersection and so as to leave (the intersection or other location in the extreme left-hand lane) lawfully available to traffic moving in the same direction as such vehicle on the roadway being entered."
2. "Whenever practicable, the left turn shall be made to the left of the center of the intersection and so as to leave (the intersection or other location) in (the extreme left-hand lane lawfully available to traffic moving in the same direction as such vehicle on the roadway being entered). That's the interpretation the government urged.

Under interpretation 2, you generally have to turn from the left lane to the left lane. Under interpretation 1, you generally may not turn from the left lane to the left lane, since you're supposed to leave the left lane available to traffic.

That's what the Georgia Supreme Court held:

It is the use of the verb "leave" and its interplay with "lawfully available to traffic moving in the same direction" in OCGA § 40–6–120(a)(2) that creates the ambiguity in the statute because of the two diametrically-opposite interpretations that can be given this word. The first interpretation is that a driver who wants to make a left turn onto a roadway with multiple lanes must make the turn in a manner that leaves the intersection or other extreme left-hand lane location lawfully available, i.e., open or clear, to traffic moving in the same direction on the roadway the driver has just entered. This interpretation applies "leave" in the context of its definition as "to permit to remain undisturbed … to permit to remain unoccupied… to let be without interference." Under this interpretation, OCGA § 40–6–120(a)(2) requires the driver to move into the right lane and leave the extreme left-hand lane available to other vehicles so they can travel unencumbered by the turning vehicle's presence. This interpretation is consistent with other rules of the road, particularly OCGA § 40–6–40(b), which requires all vehicles to "be driven in the right-hand lane then available for traffic" when they are "proceeding at less than the normal speed of traffic," a category that would include most vehicles that have just executed a left turn.

The second interpretation of OCGA § 40–6–120(a)(2) is that a driver who wants to make a left turn onto a roadway with multiple lanes must make the turn so that, when the driver departs from or "leaves" the intersection or other location, the turning vehicle is itself located in the lane farthest to the left that is lawfully available to traffic moving in that same direction. The interpretation applies "leave" in the context of its tertiary definition as "to go away or depart from." Hence, under this interpretation, the statute requires the driver making the left turn to exit, i.e., leave, the intersection or other location while the turning vehicle then proceeds to travel in the extreme left-hand lane lawfully available to traffic moving in the same direction. It was this interpretation of OCGA § 40–6–120(a)(2) that the State asserts as warranting McNair's conviction….

Although a criminal statute must be read according to the natural and obvious import of its language, our analysis above establishes that the language in OCGA § 40–6–120(a)(2) can be read as setting forth two directly contradictory ways for executing a left-hand turn onto a multi-lane roadway. Because of the language in the statute, both methods are equally plausible…. In light of the conflict in the language of OCGA § 40–6–120(a)(2), we conclude that a person of common intelligence could not determine with reasonable definiteness that the statute prohibits the making of a left turn into the right lane of a multi-lane roadway. Accordingly, we hold that OCGA § 40–6–120(a)(2) is too vague to be enforced against McNair, i.e., a driver of a vehicle making a left turn into a multi-lane roadway that lacks official traffic-control devices directing the driver into which lane to turn, see id. at (b), and is, therefore, unconstitutional under the due process clauses of the Georgia and United States Constitutions.