Jurisdictions which have directly addressed the issue of whether the setting of a traffic light clearance interval is a discretionary function have gone both ways, with the view we adopt being in a slight majority. Compare Davis v. City of Cleveland, 709 S.W.2d 613, 615 (Tenn.App. 1986) (timing sequence for traffic light interval is a discretionary act); Bjorkquist v. City of Robbinsdale, 352 N.W.2d 817, 818 (Minn.App. 1984) (same); Weiss v. Fote, 7 N.Y.2d 579, 200 N.Y.S.2d 409, 167 N.E.2d 63, 65 (1960) (same) with, Delosovic v. City of New York, 143 Misc.2d 801, 541 N.Y.S.2d 685, 688 (N.Y. 1989) (government liable for inadequate walking period for walk." "don't walk" signals); Fraley v. City of Flint, 54 Mich. App. 570, 221 N.W.2d 394, 397 (1974) (municipality liable for improper timing of traffic light interval).

A city employee's initial setting of a traffic signal's yellow light interval, and his failure to later lengthen the time sequence for the yellow light, has been considered discretionary because it was based upon the exercise of professional judgment. Davis by Davis v. City of Cleveland, 709 S.W.2d 613, 615 (Tenn.Ct.App. 1986). Whether or not to construct a drainage ditch alongside a road has also been construed as a discretionary function.

Hill v. City of Germantown, 31 S.W.3d 234 (Tenn. 2000). The Act did not define "discretionary function" leaving Tennessee courts to fill the void thereby created by falling back on the "discretionary" and "ministerial" definitions in Hale v. Johnston. Noting that other jurisdictions had interpreted their statutory "discretionary function" language, Judge Franks, dissenting in Davis v. City of Cleveland, 709 S.W.2d 613 (Tenn.Ct.App. 1986), urged adoption of a "planning-operational" test as the proper standard. Davis, 709 S.W.2d at 616.

694 S.W.2d at 950. In Davis by Davis v. City of Cleveland, 709 S.W.2d 613 (Tenn. App. 1986) the plaintiff alleged that the governmental employee responsible for setting the timing sequence on a traffic signal negligently set the yellow caution interval too short at an intersection for traffic to clear the intersection. The plaintiff alleged that this caused his collision with a tractor-trailer that entered the intersection on a red light and collided with plaintiff's vehicle which had entered the intersection with a green light.

The majority of jurisdictions considering whether a municipality is immune from suits based upon its judgment in timing traffic signals have answered in the affirmative. See, e.g., Aguehounde, 666 A.2d at 448 (citing safety considerations and professional judgment of traffic engineers); Zank, 552 N.W.2d at 722 (citing safety considerations); Ciambrone, 558 A.2d at 51 (citing safety considerations and "overall planning of traffic control"); Weiss v. Fote, 167 N.E.2d 63, 68 (N.Y. 1960) (citing safety considerations and professional judgment); Hamilton v. Town of Hamlet, 78 S.E.2d 770, 771 (N.C. 1953) (citing safety considerations and noting that immunity is the rule, not the exception); Shunkwiler v. Ohio Dep't of Transp., 643 N.E.2d 593, 594-95 (Ohio 1992); Davis v. City of Cleveland, 709 S.W.2d 613, 615 (Tenn.Ct.App. 1986) (citing professional judgment). We do not find these cases helpful because they appear to apply immunity based upon either the assertion that safety considerations and/or professional judgment were involved. Neither general safety concerns nor mere assertions of professional judgment are sufficient to confer immunity upon a municipality.

Likewise, it is possible that no exception will apply, thereby preserving governmental immunity. For a general discussion of these sections see Fretwell v. Chaffin, 652 S.W.2d 755 (Tenn. 1983); Harris v. Williamson County, 835 S.W.2d 588 (Tenn. Ct. App. 1992); Butler v. City of Dyersburg, 798 S.W.2d 776 (Tenn. Ct. App. 1990); O'Guin v. Corbin, 777 S.W.2d 697 (Tenn. Ct. App. 1980); Swafford v. City of Chattanooga, 743 S.W.2d 174 (Tenn. Ct. App. 1987); Davis v. City of Cleveland, 709 S.W.2d 613 (Tenn. Ct. App. 1986); Baker v. Seal, 694 S.W.2d 948 (Tenn. Ct. App. 1984); Mowdy v. Kelly, 667 S.W.2d 489 (Tenn. Ct. App. 1983). III

See, e.g., Johnson v. Oman Construction Co., Inc., 519 S.W.2d 782 (Tenn. 1975); O'Guin v. Corbin, 777 S.W.2d 697 (Tenn. App. 1989); Swafford v. City of Chattanooga, 743 S.W.2d 174 (Tenn. App. 1987); Davis v. City of Cleveland, 709 S.W.2d 613 (Tenn. App. 1986). Plaintiffs assert that even if the defendant initially had no duty to comply with the manual, the standards set forth in the manual became applicable upon his election to use a flagger.

The focus must remain on the policy underlying governmental immunity. If the act is one committed to coordinate branches of the government involving policy decisions not reviewable under traditional tort standards of reasonableness, the government is immune from liability even if the act was performed negligently. In adopting the "planning-operational" test which was urged by Judge Franks's dissent in Davis v. City of Cleveland, 709 S.W.2d 613, 616 (Tenn. App. 1986), we overrule Hale and its progeny to the extent that this test conflicts with the definitions set forth in Hale. Under the planning-operational test, decisions that rise to the level of planning or policy-making are considered discretionary acts which do not give rise to tort liability, while decisions that are merely operational are not considered discretionary acts and, therefore, do not give rise to immunity.

Accordingly, we consider Plaintiff's claim under section 29-20-205. See Davis by Davis v. City of Cleveland, 709 S.W.2d 613, 615 (Tenn. Ct. App. 1986) (concluding that a claim arose under section 29-20-205 and not section 29-20-203 when "[t]he substance of plaintiff's allegations is that the governmental employee who was responsible for setting the timing sequence on this traffic signal negligently set the yellow caution interval" and "that the governmental entities, through their employees, were negligent in failing to inspect and/or re-evaluate the timing sequence on this signal"); see also Fowler v. City of Memphis, 514 S.W.3d 732, 741 (Tenn. Ct. App. 2016) (citing Davis with approval and applying the same analysis).

However, the statute specifies certain circumstances in which governmental immunity is removed. Davis v. City of Cleveland, 709 S.W.2d 613, 615 (Tenn. Ct. App. 1986). Specifically, at issue in this case, Tennessee Code Annotated Section 29-20-204 provides that: