SHEPARD, Chief Justice.
Two cases before us on petitions for transfer require that we construe the provision in the Indiana Tort Claims Act which provides governmental immunity for discretionary acts.
Richey Wayne Peavler filed suit against the Monroe County Board of Commissioners, alleging “negligence in the failure to place or maintain a curve warning sign, and/or reduced speed limit sign or advisory speed limit sign on a portion of a county road.” Peavler v. Board of Commissioners of Monroe County (1986), Ind.App., 492 N.E.2d 1086, 1087. The jury returned a verdict for the county. The Court of Appeals found that the trial court erred in instructing the jury that any duty on the part of the county to post warning signs was discretionary. The Court of Appeals concluded that the county was not immune as a matter of law and held the jury should decide the question of immunity. The court remanded the cause for a new trial. Id. at 1090.
In a separate action, Ronald and Pamela Hout sued the Board of Commissioners of Steuben County, alleging that it negligently failed to place a warning sign for motorists approaching a “T” intersection. The county moved for summary judgment on the basis of governmental immunity for discretionary functions. The trial court denied the motion. In an interlocutory appeal, the Court of Appeals determined that such a decision was discretionary and directed entry of summary judgment for the county. Board of Commissioners of County of Steuben v. Hout (1986), Ind.App., 497 N.E.2d 597.
We grant transfer to resolve the conflict between districts.
I. History of Governmental Immunity
Governmental immunity developed as a common law doctrine of deference to the English monarchy. The doctrine had a dual basis in procedure and substance. Procedurally, allowing the king to be sued in his own courts was a contradiction of the king’s sovereignty. Substantively, the divine right of kings proclaimed that “the king can do no wrong.” Together, these formed the basis for the doctrine of sovereign immunity. Prosser and Keeton on Torts, § 131 at 1033 (5th Ed.1984).
The explanation for the initial acceptance of sovereign immunity in the United States is obscure. Early in the country’s history, the U.S. Supreme Court noted that no suit may be commenced against the United States without its consent. Osborn v. Bank of the United States, 22 U.S. (9 Wheat) 738, 842-43, 6 L.Ed. 204, 229 (1824). This principle was also recognized by American states, resulting in the rule that a suit may not be maintained against a state without its consent.
Several reasons for governmental immunity have been advanced: the absurdity of a wrong committed by an entire people, the idea that whatever the government did must be lawful, the theory that any government agent committing a wrongful act must have acted outside his authority, a reluctance to divert public funds to compensate for private injuries, and the inconvenience and embarrassment to the government if subjected to suit. W. Prosser, The Law of Torts, § 131 at 975 (4th Ed.1971).
Immunity for local governments such as cities, towns and counties, derived from a slightly different source. The municipal corporation had a dual character as both a subdivision of the state with governmental powers and a corporate body functioning as a private corporation. Prosser and Kee-ton on Torts, supra, at 1051. In its gov[42]*42ernmental capacity, the municipal corporation was traditionally immune from liability.
At common law, courts drew distinctions based on the dual character of the municipal corporation as both a government and a corporation. A municipal corporation acted as a government when its exercised traditional governmental functions. Those acts performed by the municipality which were analogous to acts exercised by a private corporation were proprietary functions. E. McQuillan, Municipal Corporations, § 53.02 (3rd Ed.1984). A municipality was immune when exercising its governmental functions but was not immune when acting in its proprietary capacity. See City of Kokomo v. Loy (1916), 185 Ind. 18, 112 N.E. 994.
Though arising from municipal law, this distinction was applied to state immunity as well. To determine whether the act was a corporate or governmental undertaking, the manner in which the power was conferred, the obligations which naturally flowed from proprietorship and the purpose for which the power was granted and exercised were considered. Aiken v. City of Columbus (1906), 167 Ind. 139, 78 N.E. 657 Duties administered solely for public benefit, such as public health, charities, schools, protection of property against fire and maintenance of the peace were governmental undertakings.
The classification of functions as governmental or proprietary was elusive and uncertain and often led to inconsistent results. This Court abandoned the governmental/proprietary distinction in Campbell v. State (1972), 259 Ind. 55, 284 N.E.2d 733. In addressing the vitality of the doctrine of sovereign immunity in Indiana, this Court determined that the purpose for which the doctrine existed had long since vanished. Id. at 57-58, 284 N.E.2d at 736. The Court held the defense of sovereign immunity was no longer available to the state for either governmental or proprietary functions. Id. at 63, 284 N.E.2d at 737. The Court noted that while certain common law immunities, such as those for judicial and legislative decisions must remain, other instances giving rise to state liability should be considered by the legislature. Id. at 61-62, 284 N.E.2d at 737. Two years later, the General Assembly enacted the Indiana Tort Claims Act. 1974 Ind.Acts, P.L. 142 § 1.
II. Indiana Tort Claims Act
The Indiana Torts Claims Act (ITCA) provides that governmental entities may be liable for torts committed by its agencies and its employees. Ind.Code §§ 34-4-16.-5-1 to 20 (Burns 1986 Repl.). The ITCA protects governments from liability in certain circumstances. Among other more specific exceptions, “[a] government entity or an employee acting within the scope of his employment is not liable if a loss results from: (6) The performance of a discretionary function.” Ind.Code § 34-4-16.5-3(6). Each of the cases at bar turns on the meaning of discretionary function.
III. Approaches to Discretionary Function
Governmental immunity has generated a great deal of discussion in state and federal jurisdictions. Out of this debate, several approaches have emerged to determine whether an act is discretionary and thus entitled to immunity. While these approaches are instructive, the purpose and policy underlying governmental immunity must be the cornerstone for evaluating any claim of governmental immunity.
A. The Ministerial/Discretionary Distinction. Courts have attempted to distinguish immune governmental functions from those which expose the government to liability by describing activities as ministerial or discretionary.
A duty is discretionary when it involves on the part of the officer to determine whether or not he should perform a certain act, and if so in what particular way, and in the absence of corrupt motives, in the exercise of such discretion, he is not liable. His duties, however, in the performance of the act, after he has once determined that it shall be done, are ministerial, and for negligence in such performance, which results in injury, he may be liable in damages.
[43]*43Adams v. Schneider (1919), 71 Ind.App. 249, 255-56, 124 N.E. 718, 720.
This common law distinction has found favor within our Court of Appeals since the ITCA passed. A duty is discretionary when the officer must determine whether he should perform a certain act, and, if so, in what manner. Mills v. American Playground Device Co. (1980), Ind.App., 405 N.E.2d 621. Performance of a discretionary function requires judgment and choice and involves what is proper and just under the circumstances. Rodman v. City of Wabash (1986), Ind.App., 497 N.E.2d 234. A ministerial act is performed in a prescribed manner, in obedience to the mandate of legal authority, without the exercise of judgment upon the propriety of the act. Coghill v. Badger (1981), Ind.App., 418 N.E.2d 1201, 1211 n. 9; Galey v. Board of Commissioners (1910), 174 Ind. 181, 183, 91 N.E. 593, 594; Flowney v. Jeffersonville (1861), 17 Ind. 169, 174. Ministerial acts “are those done by officers and employees who are required to carry out the orders of others or to administer the law with little choice as to when, where, how or under what circumstances their acts are to be done.” Restatement, supra § 895D comment h. Under this dichotomy any governmental act involving choice, judgment or decision-making is discretionary and immune from tort liability. Only those acts which require no judgment are ministerial and subject to tort liability.
This Court has recognized that the application of this standard is unclear. Loy, 185 Ind. at 23, 112 N.E. at 996. This difficulty has also been noted by scholars and commentators.
It seems almost impossible to draw any clear and definite line, since the distinction, if one exists, can be at most one of degree. “It would be difficult to conceive of any official act, no matter how directly ministerial, that did not admit of some discretion in the manner of its performance, even if it involved only the driving of a nail.”
W. Prosser, The Law of Torts, supra § 132 at 990 (quoting Ham v. City of Los Angeles County, 46 Cal.App. 148, 162, 189 P. 462, 468 (1920)). If discretionary functions included every act which involves any element of choice, judgment or ability to make responsible decisions, every act would fall within the exception. Sterling v. Bloom, 111 Idaho 211, 227, 723 P.2d 755, 771 (1986).
B. Planning vs. Operation. Another method of analysis has emerged primarily from interpretation of federal statutory immunity. In 1946, the United States gave consent to be sued in tort when it enacted the Federal Tort Claims Act, 28 U.S.C. § 1346(b) (1982) (FTCA). The FTCA generally exposes the government to tort liability but provides immunity for certain enumerated acts and for any claim based on the exercise of a “discretionary function or duty.” 28 U.S.C. § 2680(a) (1982).
In interpreting discretionary functions, the U.S. Supreme Court has rejected the distinction between governmental and proprietary functions:
Furthermore, the Government in effect reads the statute as imposing liability in the same manner as if it were a municipal corporation and not as if it were a private person, and it would thus push the courts into the “non-governmental” —“governmental” quagmire that has long plagued the law of municipal corporations. A comparative study of the cases in the forty-eight States will disclose an irreconcilable conflict. More than that, the decisions in each of the States are disharmonious and disclose the inevitable chaos when courts try to apply a rule of law that is inherently unsound.
Indian Towing Co. v. United States, 350 U.S. 61, 65, 76 S.Ct. 122, 124, 100 L.Ed. 48, 53-54 (1955).
Rather, the Supreme Court has determined which acts are entitled to immunity by distinguishing acts performed at the planning level from acts performed at the operational level. The federal government is not subject to liability when the alleged negligence arises from decisions which are “responsibly made at a planning rather than operational level and involved considerations more or less important to the practi[44]*44cability” of the government’s program. Dalehite v. United States, 346 U.S. 15, 42, 73 S.Ct. 956, 971, 97 L.Ed. 1427, 1444 (1953).
Thus, immunity for discretionary functions under this analysis does not extend to all acts involving choice or judgment. The FTCA protects the discretion of the executive or the administrator to act according to his or her judgment of the best course, a concept of substantial historical ancestry in American law. The discretionary function or duty “includes more than the initiation of programs and activities. It also includes determinations made by executives or administrators in establishing plans, specifications or schedules of operations.” Id. at 35-36, 73 S.Ct. at 968, 97 L.Ed.2d at 1440.
C. Separation of Power and Purposes of Governmental Immunity. Ultimately, the determination of whether a governmental action is immune as a discretionary function must be based on the purposes and policy underlying governmental immunity. The early purposes of governmental immunity largely have been eliminated. See Campbell, 259 Ind. at 61, 284 N.E.2d at 736. While the historical reasons supporting the doctrine of sovereign immunity are no longer vital, governmental immunity under some circumstances still serves valid purposes. Common law forms of immunity, such as immunity for legislative and judicial functions, remain even absent statutory immunity. Restatement, supra § 895B, comment b at 402. Even as it abandoned the governmental/proprietary distinction, this Court acknowledged the continuing vitality of such forms of governmental immunity. Campbell 259 Ind. at 62-63, 284 N.E.2d at 737.
The policy underlying governmental immunity is the fundamental idea that certain kinds of executive branch decisions should not be subject to judicial review. The separation of powers doctrine forecloses the courts from reviewing political, social and economic actions within the province of coordinate branches of government. In this way, the discretionary function exception articulates “a policy of preventing tort actions from becoming a vehicle for judicial interference with decision-making that is properly exercised by other branches of the government....” Blessing v. United States, 447 F.Supp. 1160, 1170 (E.D.Penn.1978) (interpreting FTCA discretionary function exception). See also Carter v. City of Stuart, 468 So.2d 955, 956 (Fla.1985) (discretionary functions immune because “coordinate branches of government may not be subject to scrutiny by judge or jury as to the wisdom of their performance”) (quoting Commercial Carrier Corp. v. Indiana River County, 371 So.2d 1010, 1022 (Fla.1979)); Ostendorf v. Kenyon, 347 N.W.2d 834 (Minn.App.1984) (pur¡-pose of discretionary function exception is that courts are not an appropriate forum to review and second guess acts of government which involve exercise of judgment); Whitney v. City of Worcester, 373 Mass. 208, 366 N.E.2d 1210 (1977) (judicial abstention from policy formation of coordinate branches required because inquiries into political discretion would jeopardize quality and efficiency of government); Industrial Indemnity Co. v. Alaska, 669 P.2d 561 (Alaska 1983) (basic policy decisions are vested in politically responsive branches).
Governmental immunity for discretionary functions also avoids inhibiting the effective and efficient performance of governmental duties. Policy-making activities lie at the heart of governance and such essential acts should not be subject to judicial second-guessing or harassment by the actual or potential threat of liability litigation. Tort immunity for basic planning and policy-making functions is necessary to avoid the chilling effect on the ability of the government to deal effectively with difficult policy issues which it confronts daily. C & D Partnership v. City of Gahanna, 15 Ohio St.3d 359, 474 N.E.2d 303 (1984).
Moreover, the traditional tort standard of negligence does not provide an adequate basis for evaluating certain governmental decisions. As the district court in Blessing said:
[T]he judiciary confines itself ... to adjudication of facts based on discernible objective standards of law. In the context of tort actions ... these objective stan[45]*45dards are notably lacking when the question is not negligence but social wisdom, not due care but political practicability, not unreasonableness but economic expediency. Tort law simply furnishes an inadequate crucible for testing the merits of social, political, or economic decisions.
Blessing, 447 F.Supp. at 1170-72. See also Wainscott v. State, 642 P.2d 1355 (Alaska 1982) (discretionary exception recognizes that courts are ill-equipped to investigate and balance numerous factors in legislative or executive decisions); Cairl v. State, 323 N.W.2d 20 (Minn.1982) (negligence action not an appropriate forum to review exercise of judgment by other branches).
Immunity for discretionary functions, however, does not protect all mistakes of judgment. The discretionary function exception insulates only those significant policy and political decisions which cannot be assessed by customary tort standards. In this sense, the word discretionary does not mean mere judgment or discernment. Rather, it refers to the exercise of political power which is held accountable only to the Constitution or the political process. Miller v. United States, 583 F.2d 857, 866-67 (6th Cir.1978).
This interpretation of the discretionary function exception also comports with the Restatement (Second) of Torts:
Even when a State is subject to tort liability, it and its governmental agencies are immune to liability for acts and omissions constituting
(a) the exercise of a judicial or legislative function, or
(b) the exercise of an administrative function involving the determination of fundamental government policy.
Restatement, supra § 895B(3).
The distinction between planning and operational functions relates well to the purposes of governmental immunity. It requires an inquiry into the nature of the governmental act and the decision-making process involved. Merely labeling an action as planning or operational, without more, cannot pass for analysis. The critical inquiry is “not merely whether judgment was exercised but whether the nature
of the judgment called for policy considerations.” Blessing, 447 F.Supp. at 1178 (quoting Griffin v. United States, 500 F.2d 1059, 1064 (3rd Cir.1974)). In many cases, courts have looked to the purposes of immunity in determining whether an act is planning or operational.
Under the planning/operational dichotomy, the type of discretion which may be immunized from tort liability is generally that attributable to the essence of governing. Enghauser Mfg. Co. v. Eriksson Engineering, 6 Ohio St.3d 31, 451 N.E.2d 228 (1983). Planning activities include acts or omissions in the exercise of a legislative, judicial, executive or planning function which involves formulation of basic policy decisions characterized by official judgment or discretion in weighing alternatives and choosing public policy. Marrek v. Cleveland Metroparks Board. of Commissioners, 9 Ohio 3d 194, 459 N.E.2d 873 (1984). Government decisions about policy formation which involve assessment of competing priorities and a weighing of budgetary considerations or the allocation of scarce resources are also planning activities. Industrial Indemnity Co., 669 P.2d at 564-65.
The distinction between planning and operational functions is a standard, rather than a precise rule. 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 iron) liability even if the act was performed negligently.
IV. Policy-Based Analysis of Immunity
The ministerial/discretionary test does not advance the public policy of government immunity because it does not consider the type of decision protected by immunity. Rather, it considers only the resulting conduct and attempts to label that conduct. The ministerial/discretionary test defines “discretionary” in the negative: anything which is non-ministerial is discretionary. The test does not require an affirmative finding that the governmental action arose [46]*46from the type of policy-making decision protected by governmental immunity. It operates by process of elimination, removing ministerial acts from the more general category of discretionary, immune acts.
The discretionary function exception of the ITCA removes discretionary acts from the broader spectrum of liability. This requires an affirmative finding that the governmental act is of the type intended to be protected by immunity. The planning/operational test provides a better framework for such an analysis. This test advances the policy underlying governmental immunity and allows consideration of the nature of the challenged decision. In defining discretionary acts immune under the ITCA, we reject the ministerial/discretionary test in favor of the planning/operational test, to be applied in light of the policy and rational supporting governmental immunity.
The issue of whether an act is discretionary and therefore immune is a question of law for the court’s determination. The question may require an extended factual development1, but the essential inquiry is whether the challenged act is the type of function which the legislature intended to protect with immunity. This determination should be made by the court.
Discretionary immunity must be narrowly construed because it is an exception to the general rule of liability. Larson v. Ind. School Dist. No. 314, 289 N.W.2d 112 at 121 (Minn.1979). The governmental entity seeking to establish immunity bears the burden of proving that the challenged act or omission was a policy decision made by consciously balancing risks and benefits. See Little v. Wimmer, 303 Or. 580, 739 P.2d 564 (1987); Johnson v. State, 69 Cal. 2d 782, 794 n. 8, 447 P.2d 352, 361 n. 8, 73 Cal.Rptr. 240, 249 n. 8 (1968).
In deciding whether the function is the type intended to benefit from immunity, the court should look to the purposes of immunity to determine whether those purposes would be furthered by extending immunity to the act in question. Factors which would, under most circumstances, point toward immunity, include:
1. The nature of the conduct—
a) Whether the conduct has a regulatory objective;
b) Whether the conduct involved the balancing of factors without reliance on a readily ascertainable rule or standard;
c) Whether the conduct requires a judgment based on policy decisions;
d) Whether the decision involved adopting general principles or only applying them;
e) Whether the conduct involved establishment of plans, specifications and schedule; and
f) Whether the decision involved assessing priorities, weighing of budgetary considerations or allocation of resources.
2. The effect on- governmental operations—
a) Whether the decision affects the feasibility or practicability of a government program; and
b) Whether liability will affect the effective administration of the function in question.
3. The capacity of the court to evaluate the propriety of the government’s action—
Whether tort standards offer an insufficient evaluation of the plaintiff’s claim.
Immunity assumes negligence but denies liability. Thus, the issues of duty, breach and causation are not before the court in deciding whether the government entity is immune. If the court finds the government is not immune, the case may yet be decided on the basis of failure of any ele[47]*47ment of negligence. This should not be confused with the threshold determination of immunity. See Prosser and Keeton, The Law on Torts, supra § 131 at 1043.
V. Resolution of the Cases
Both Peavler and Hout allege that the respective defendant counties were negligent for failing to place traffic control devices warning motorists of dangerous sections of county roads. Both counties answer that such a decision is a discretionary function and that each county is therefore immune from any liability arising from a failure to place a warning sign.
The counties argue that, while failure to maintain a previously posted traffic sign is non-discretionary, the original decision to install one is discretionary. Clearly, there are cases on either end of the spectrum which will fall automatically into the category of discretionary or non-discretionary functions. Such is the case of the failure to properly maintain a warning sign. It does not follow, however, that the decision to post such a sign is automatically discretionary.
While warning signs are posted to further the safety of the community, they are also regulatory devices, and they may have a penal effect on violators. While the Indiana Manual on Uniform Traffic Control Devices offers guidelines for warning signs, the Manual does not “mandate the use of any control devices or procedures at a particular location.” Indiana Department of Highways, Indiana Manual on Uniform Traffic Control Devices, § 1A-1 (1988). The decision may involve gathering data regarding traffic flow, average speed, and other factors. It may also involve weighing priorities to determine if safety considerations outweigh inconveniences to individual motorists, and determining whether uniformly marking all similar sites can be accommodated within a given budget.
While potential liability may have some effect on this government function, the government is still shielded by immunity for actual policy-making decisions regarding warning signs. Thus, the government is exposed to liability only when no policy oriented decision-making process has been undertaken.
Tort standards of reasonableness do not provide an adequate basis for evaluating the failure to erect a warning sign if that failure arises from an actual, affirmative policy decision. If the decision is based on professional judgment, however, rather than policy oriented decision-making, traditional tort standards for professional negligence afford a basis for evaluation. Thus, a county’s considered decision to entrust placement of traffic control devices to a traffic engineer is not reviewable under tort standards, while the engineer’s subsequent decisions as to warning signs are reviewable under tort standards of professional negligence. See Driscoll v. United States, 525 F.2d 136 (9th Cir.1975).
Considering the nature of the conduct, the effect on government operations, and the capacity of the courts to evaluate the propriety of the government’s actions, we cannot say that governmental policy is so clearly implicated by decisions regarding placement of warning signs that all such decisions are discretionary under the ITCA as a matter of law. Had the legislature intended for such an act to be immune outside the parameters of the discretionary function exception, it could have provided specific immunity. See e.g., Iowa Code Ann. § 668.10, subd. 1 (West 1985).
The discretionary nature of a decision to place a warning sign must be determined case by case. Immunity may be established by government defendants who can show that the challenged decision was discretionary because it resulted from a policy oriented decision-making process. If the counties engaged in this decision-making process, the courts may not judge the wisdom of their decisions. That judgment is left to the political process.
The defendants here seek to establish the defense of immunity. Each bears the burden to show that a policy decision, consciously balancing risks and benefits, took place. Neither defendant county presented evidence to show that its decision [48]*48regarding the warning signs was the result of such a process.
The trial court in Peavler submitted the case to the jury with an instruction that any duty on the part of the county to post warning signs was discretionary. While the county might well have been entitled to a verdict on negligence or contributory negligence issues, the Court of Appeals concluded it could not say that such error was harmless because the jury’s verdict may have been based on the erroneous instruction. Peavler, 492 N.E.2d at 1090. We agree.
The Hout case was decided on the basis of a motion for summary judgment. The record before us consists of the complaint and answer, the parties’ interrogatories, the motion for summary judgment and motion in opposition together with supporting memoranda. The county did not present evidence that the “T” intersection had been considered by the board of commissioners or that is was part of a policy process in which elected officials played a key role. It did not introduce minutes of board meetings where the need for a warning sign was rejected or present testimony of commissioners regarding the decision-making process involved. It did not introduce a comprehensive ordinance, studies or surveys of the area in question which showed that this area had been evaluated and a warning sign had been deemed unnecessary.2
The county presented no evidence from which we can evaluate the nature of the board’s conduct in failing to erect a warning sign, the potential effect of liability on county operations, or the capacity of the court to judge the county’s action. We cannot determine from this record whether the failure to erect a warning sign arose from a judgment based on policy considerations. The record presented therefore does not support the conclusion that no question of material fact remains regarding the county’s immunity. The excellent opinion of Judge Sand in denying the county’s motion was correct.
Failure to engage in this decision-making process does not automatically result in liability. The county simply is not shielded by immunity if the failure to erect a warning sign did not result from a policy decision consciously balancing risks and advantages.
If the county in either case can present evidence that the commissioners engaged in a policy oriented decision-making process and determined, for whatever reason, that a warning sign should not be posted, the courts will not second-guess their judgment. On remand, the counties bear the burden to demonstrate the discretionary nature of the decision in order to prevail on a claim of immunity.
The opinions of the Court of Appeals are vacated. The judgment of the trial court in Peavler is reversed. The judgment of the trial court denying summary judgment in Hout is affirmed. Both causes are remanded for further proceedings consistent with this opinion.
DeBRULER, GIVAN and DICKSON, JJ., concur.
PIVARNIK, J., dissents with opinion.