On appeal from the denial of a Post-Conviction Relief Petition, the Court of Appeals in an opinion by Sullivan, J., White, J., concurring in result, Buchanan, J., dissenting, reversed the trial court. The State, as Appellees, petitioned this Court for transfer. We heard oral argument. We grant transfer and reverse the Court of Appeals and affirm the judgment of the trial court.
*548Appellants were convicted of Robbery. Certain items of evidence were seized following the stopping of Appellants’ automobile. Appellants contend that the trial court erred in admitting the seized evidence. The trial court held that the arresting officers acted lawfully in stopping Appellants’ car despite the absence of probable cause to arrest. It is this conclusion which the Appellants challenge.
At 10:02 p.m. of the night in question, Indiana State Police Sergeant Cox and Trooper Fox were on routine patrol duty in an unmarked police car when they received a radio dispatch informing them that seven (7) minutes earlier a robbery had been committed at the King’s Crown Motel of West Lafayette. A second radio report was received. From these two reports the officers learned that the suspects were two male Negroes and that they were possibly traveling northwest.
At the time of these reports, the officers were located on State Road 18, four miles east of U.S. Highway 231, and fifteen miles northwest of the scene of the crime. Knowing Highway 231 to be a major link-up between Highway 52 and Interstate 65 (the most direct route to a possible escape location such as Chicago), the officers proceeded directly to the intersection of Highways 18 and 21.
It took the officers about three minutes to reach this point. They observed in the next two to four minutes two cars heading north. When a third car came by, the officers thought the driver, apparently the only occupant of the car, might be a Negro.
At this time, the officers had deduced that if the suspects were indeed enroute directly to Chicago, they could be observed at just this point. Sergeant Cox testified that:
“We knew that a crime had been committed. We knew from the time element that the individual we were looking for had time to be at about this location at about this time.”
Acting upon this hypothesis, the officers decided to follow the automobile. After receiving a third radio dispatch stating *549that one suspect had used a sawed-off shotgun or pistol in the robbery, the officers overtook the car they were following in an unsuccessful attempt to get a better look at the driver. Then, the officers proceeded a short distance to an intersection located at the South edge of the town of Wolcott, and parked in a service station drive. When the car they had been observing stopped at the intersection, the improved lighting conditions allowed one officer to become certain that the driver was a Negro, although the other officer still was not certain.
The officers then used an inside red light to stop the car at the side of the road. The driver (Appellant Williams) left his car and approached. Trooper Fox, the driver of the police car, asked the man to stop. The two officers approached the car, one on each side. As Trooper Fox asked to see the driver’s license, he looked into the stopped car and saw a person hiding on the back seat. As the second man (Appellant Rogers) exited the right door of the car, that door was left open and Sergeant Cox saw a sawed-off shotgun in plain view. These occurrences led the police officers to place the Appellants under arrest and to seize the incriminating evidence used at trial. The Appellants were later positively identified as the robbers by employees of the motel.
There is here no contention that the formal arrest of the Appellants was without probable cause. [Indiana law defines arrest as the taking into custody of a person for the purpose of having him answer for a public offense. IC 1971, 35-1-17-1, [Burns Ind. Ann Siat. § 9-1004 (1956 Repl.).] There is no contention that the seizure of the incriminating evidence was not lawful. The sole contention is that the initial stopping of the Appellants’ car was unlawful and that, therefore, the fruits of this unlawful seizure must be excluded from the trial. Wong Sun v. United States (1963), 371 U.S. 471; Mapp v. Ohio (1961), 367 U.S. 643; Weeks v. United States, (1914), 232 U.S. 383.
*550*549The legal question that confronts us, to be very specific, *550is: did the police officers have the right to stop the motorist on the basis of the suspicion created by the meager facts received over the radio and the police officers calculations from those facts ? After the stopping of the Appellants’ car, it became immediately apparent without a search, but from open observation (the shotgun and the passenger hiding in the car) that probable cause existed for the arrest of the Appellants. If the stopping was legal, then all that followed was legal. As Justice Hunter has said, in situations of this sort the question is “whether the facts known at the time he (a police officer) stopped the car were sufficient to warrant a man of reasonable caution in the belief that an investigation was appropriate.” Luckett v. State (1972), 259 Ind. 174 at 180; 284 N. E. 2d 738 at 742. Justice Hunter went on to observe that in the situation presented in Luckett “we find nothing unreasonable in permitting the investigating officer to request that an operator’s license be produced by the driver of the vehicle. . . . Furthermore, it should certainly be permissible for the officer to observe the occupants of the automobile, and to take cognizance of any items in the automobile which are in plain view.” Luckett, supra, at 742.
In fact, this case presents squarely to us the question whether or not under similar circumstances a roadblock could be set up at certain points where it has reasonably been calculated that fleeing robbers might be apprehended. Justice Jackson of the United States Supreme Court, dissenting from the approval of a seizure and search, realized and noted the problem, commenting as follows:
“If we assume, for example, that a child is kidnapped and the officers throw a roadblock about the neighborhood and search every outgoing car, it would be a drastic and undiseriminating use of the search. The officers might be unable to show probable cause for searching any particular car. However, I should candidly strive hard to sustain such an action, executed fairly and in good faith, because it might be reasonable to subject travelers to that indignity if it was the only way to save a threatened life and detect a vicious *551crime. But I should not strain to sustain such a roadblock and universal search to salvage a few bottles of bourbon and catch a bootlegger.”
Brinegar v. United States (1948), 388 U.S. 160 at 183. However, the suggestion by Justice Jackson that the right to stop depends upon the enormity of the crime creates an uncertain and hazardous standard for police officers to follow.
In Terry v. Ohio (1968), 392 U.S. 1, the United States Supreme Court had before it a situation in which a police officer with thirty (30) years experience on a particular beat became suspicious of the actions of two men who repeatedly and alternately made numerous round-trip strolls past a store window. The officer accosted these men when they were conferring with a third man with whom they had previously conferred during their strolls. In a brief “pat down” or “frisk” the officer discovered concealed weapons on two of the men. In upholding this particular “search and seizure” the Supreme Court said that:
“. . . in justifying the particular intrusion the police officer must be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant that intrusion. The scheme of the Fourth Amendment becomes meaningful only when it is assured that at some point the conduct of those charged with enforcing the laws can be subjected to the more detached, neutral scrutiny of a judge who must evaluate the reasonableness of a particular search or seizure in light of the particular circumstances. And in making that assessment it is imperative that the facts be judged against an objective standard; would the facts available to the officer at the moment of the seizure ‘warrant a man of reasonable caution in the belief’ that the action taken was appropriate? CF. Carroll v. United States, 267 US 132, 69 L. Ed. 543, 45 S. Ct. 280, 39 ALR 709 (1925); Beck v. Ohio, 379 US 89, 96-97, 13 L. Ed. 2d 142, 147, 148, 85 S. Ct. 223 (1964).” Terry supra, at 392 U.S. 21-22.
Our society has a right to protect itself. What is “unreasonable” under the Fourth Amendment is a function of the totality of conditions existing within our society at any moment in history. Social interests under *552the police power should give law officers the right to stop users of the highways to check, for instance, their right to use the highway or to check the vehicles for safety standards. Myricks v. United States (1967), 370 F. 2d 901 (5th Cir.) (Texas); Lipton v. United States (1965), 348 F. 2d 591 (9th Cir.) (California); State ex rel. Berger v. Cantor (1971), 13 Az. A. 555, 479 P. 2d 432 (Arizona Ct. of App.) (license, registration, safety checks); Mincy v. District of Columbia (1966), 218 A. 2d 507; City of Miami v. Aronovitz (1959), 114 So. 2d 784 (Florida) (roadblock for license check); Commonwealth v. Mitchell (1962), 355 S. W. 2d 686 (Kentucky) (roadblock for license check); State v. Kabayama (1967), 98 N. J. Super. 85, 236 A. 2d 164 (New Jersey) (roadblock for safety inspection); Cox v. State (1944), 181 S. W. 2d 338 (Tennessee). Indeed, in California, a state intensively affected by the automobile, the police have been permitted to stop a car on “founded suspicion,” Wilson v. Porter (1966), 361 F. 2d 412, 415 (9th Cir.), and to effect a brief detention of anyone — including motorists— for investigative purposes whenever “reasonably . . . necessary to the proper discharge of [their duty].” Bramlette v. Superior Court (1969), 273 Cal. App. 2d 799, 805, 78 Cal. Rptr. 532, 535 (Ct. of Appeals).
Similarly, we have the searches of passengers boarding airplanes. United States v. Legato (1973), 13 Cr. L. 2303 (5th Cir.); United States v. Bell (1972), 464 F. 2d 667 (2nd Cir.) cert. denied, 409 U.S. 991 (1973); United States v. Lindsey (1971), 451 F. 2d 701 (3d Cir.) cert. denied, 405 U.S. 995 (1972); United States v. Rivera (1973), 13 Cr. L. 2234 (D. C. N. Y.) Such procedures have been very effective in deterring “hijacking”, and insofar as our limited observation reveals have met with the traveling public’s approval.
We offer the following hypothetical: At a party of, say, twenty or so persons a valuable diamond ring is discovered to be missing from the person of one of the guests. Absent any more information, there would not be probable cause *553to detain one specific individual from among the persons present, but would it be unreasonable to detain all the persons present? A distinction may exist between what is a reasonable restraint of an individual and what is a reasonable restraint of an identifiable group. The interference with citizen liberty described in the above situations may be rationalized on the basis that although there is not probable cause for suspicion of one specific person, probable cause does exist as to an identifiable group (e.g.) those persons using the highways at a certain time and certain place in the aftermath of a crime, those persons boarding airplanes, those persons at the party.
It has been said that constitutional interpretation must conform to the changes which progress has wrought in our society since the adoption of the Constitution. The classic formulation is that of Chief Justice Marshall’s:
“. . . we must never forget that it is a constitution we are expounding. . . .
... a constitution intended to endure for ages to come, and, consequently, to be adapted to the various crises of human affairs. . .
M’Culloch v. Maryland (1819), 4 Wheat. 314, 407, 515, 4 L. Ed. 579, 602, 603. The automobile has made an alteration in our way of life unforseen and unforeseeable by the Founding Fathers. It is our duty to be rational and sensible in our constitutional interpretation so that modern society is not damaged or injured by an irrational and unrealistic refusal to recognize the necessities brought about by these changes. The primary purpose of government is the protection of society. An instrument should not be so interpreted as to thwart that main objective.
If the police officers under the facts before us had observed the incriminating evidence inside the car while it was parked on the roadside, there would be no question here as to the right of the officers to arrest the driver and the occupant’and to make a further search. United States v. Robinson (1973), 42 LW 4055.
*554As we previously stated, the question before us is whether or not suspicion such as the officers had in this case is a sufficient basis for the stopping of an automobile upon the public highway. We believe that it is, and that such pronouncement is a reasonable interpretation of constitutional rights which are rights that belong to the public [the State] as well as to a defendant in a criminal case. Courts have to balance out the rights and have done so in the past. We think that this case falls within the purview of Luckett, supra, and Terry, supra. The judgment of the trial court is affirmed.
Givan, J. concurs; Hunter, J., concurs in result with opinion; Prentice, J., dissents; DeBruler, J., dissents with opinion.