This court allowed the state of South Dakota to appeal a suppression order entered by the Sixth Judicial Circuit Court. The trial judge held that Highway Patrolman Steven Kenoyer (Kenoyer) did not have probable cause to stop and arrest Jim Dale Anderson (Anderson) and that all evidence derived from the stop and arrest including the breathalyzer and blood test results, should be suppressed. We reverse and remand.
The Wall, South Dakota, Police Department telephoned Kenoyer at his home in Philip, South Dakota, at approximately 8:13 a.m. on March 17, 1983. The Wall Police Chief told Kenoyer that an intoxicated driver had left a Wall gas station headed east toward Philip in a black International Scout. Kenoyer drove west out of Philip and located the Scout between Philip and Wall. He followed it for two miles back *889into Philip and observed the Scout’s speed vary from 45 to 55 miles per hour and saw it cross the white shoulder line once. When the Scout entered Philip it stopped at a stop sign and turned right. Kenoyer noticed that the vehicle’s right taillight and right brake light failed. At this point, Ke-noyer stopped the vehicle on the basis of the Wall Police Department tip and the equipment violations he observed.
The trial court concluded that in spite of the suspicion raised by the police tip, the facts and circumstances known to Kenoyer at the time of the stop did not justify the stop or the arrest. The trial court’s Conclusion of Law II reads:
The stop by Trooper Kenoyer lacked probable cause in that once he investigated as a result of the Chief of Police’s tip, the situation presented to him did not have numerous independent factors outside of the police tip on which to base his findings for probable cause. Once he made the stop all of the factors that he articulated and the sobriety tests which he normally relied on mitigated against probable cause except for the PBT and thus Trooper Kenoyer lacked probable cause for both the initial stop and for the subsequent arrest.
The trial court distinguished probable cause to stop from probable cause to arrest, but failed to distinguish the standards.
This court recently examined the requisite grounds for a justifiable routine traffic stop in State v. Anderson, 331 N.W.2d 568 (S.D.1983). The Anderson Court cited and quoted a Minnesota case, Marben v. State, Dept. of Public Safety, 294 N.W.2d 697, 699 (Minn.1980), for the proposition that:
[A] police officer may not stop a vehicle without a reasonable basis for doing so. Consistent with the principles set out in Terry v. Ohio, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968), the officer must have a specific and articulable suspicion of a violation before the stop will be justified.
331 N.W.2d at 570 (emphasis in original).
In Anderson, this court adopted the Minnesota Supreme Court’s definition of the “reasonable suspicion” standard which was taken in part from People v. Ingle, 36 N.Y.2d 413, 369 N.Y.S.2d 67, 330 N.E.2d 39 (1975), in which the New York Court stated:
“It should be emphasized that the factual basis required to support a stop for a ‘routine traffic check’ is minimal .... A1I that is required is that the stop be not the product of mere whim, caprice, or idle curiosity. It is enough if the stop is based upon ‘specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant [the] intrusion[.]’ ”
36 N.Y.2d at 420, 369 N.Y.S.2d at 74, 330 N.E.2d at 44 (citation omitted). The reasonable suspicion standard was thus applied to routine traffic stops in South Dakota, including stops involving suspicion of DWI. Anderson, 331 N.W.2d at 570. This court previously applied the reasonable suspicion standard in other factual situations. See State v. Soft, 329 N.W.2d 128, 129 (S.D.1983); State v. Coe, 286 N.W.2d 340 (S.D.1979); State v. Boardman, 264 N.W.2d 503 (S.D.1978).
The arresting officer in Anderson, an experienced police officer with training in detection of drinking drivers, observed the defendant veer into snow-packed areas of the road and weave back to the clear lane. This activity afforded a specific and articulable reason to stop the defendant’s car to determine whether’ he was driving under the influence of an alcoholic beverage. 331 N.W.2d at 570. The reasonable suspicion standard was also applied in Whitson v. Department of Public Safety, 346 N.W.2d 454 (S.D.1984). The arresting officer in Whitson observed the defendant ignore a “right turn only” lane marker and force two other vehicles to slow down to avoid a collision. This court held that in the absence of a factual basis to support the argument that a stop was random, the argument that it was unlawful is without merit. Id., citing Delaware v. Prouse, 440 U.S. 648, 99 S.Ct. 1391, 59 *890L.Ed.2d 660 (1979). Circumstances giving rise to a “ ‘specific and articulable suspicion of a [traffic] violation’,” are also sufficient to justify the investigatory stop of a vehicle. Whitson, 346 N.W.2d 454 at 456 (S.D.1984); Anderson, 331 N.W.2d at 570. Either the Police Chief's tip, even though based on hearsay, or the equipment violation on Anderson’s car was sufficient to justify the stop in this case.
Kenoyer stopped the Scout in a parking lot and he and the driver both emerged from their vehicles. Kenoyer requested a driver’s license and vehicle registration and Anderson produced both immediately. Ke-noyer asked Anderson to seat himself in the patrol car and Kenoyer proceeded to issue Anderson a warning ticket for equipment violations. As Kenoyer wrote the ticket, he detected a strong odor of alcohol. Anderson admitted at that time that he drank the night before. Kenoyer asked Anderson to take a series of four physical sobriety tests in order to determine the state of Anderson’s physical and mental dexterity. Anderson passed by (1) correctly reciting the alphabet, (2) correctly counting from one to ten and back from ten to one, (3) performing the Rhomberg balancing test, and (4) walking heel to toe. Upon Anderson’s satisfactory completion of the physical sobriety tests, Kenoyer asked him to get back into the patrol car and take a preliminary breath test with portable breath testing equipment (PBT).
Dr. Joel Padmore is the State Chemist and Director of the South Dakota State Chemical Laboratory. His agency has provided blood alcohol analyses for law enforcement agencies since 1951 and has provided technical support and training for breath testing devices since the late 1960’s and early 1970’s. In 1979, the State Chemistry Lab assumed responsibility for supervision and maintenance of all evidentiary breath testing devices and received legislative approval for that function as of July 1, 1980. Under its statutory responsibilities, the State Chemistry Lab evaluated portable breath testing devices for the South Dakota Department of Public Safety in the spring of 1981. In a deposition taken for this case by Anderson’s attorney, Dr. Pad-more explained the PBT.
Preliminary breath testing is accomplished through the use of portable devices that, according to Dr. Padmore, are as accurate statistically as intoxilyzers, the results of which are currently used in this state as evidence to show blood alcohol levels in excess of .10 and violations of SDCL 32-23-1. Both machines measure breath alcohol content in grams per hundred cubic centimeters on an equivalent blood alcohol analysis, commonly called weight percent. The intoxilyzers and the PBTs used in South Dakota are both accurate to within two to three percent, which means that the variance when measuring a test standard of .10 is between .098 and .12. Dr. Padmore tested the PBTs under simulated field conditions and found them no more susceptible to error than intoxilyzers operated in fixed positions, given equally competent test administration. Both devices, if operated improperly, can indicate a lower breath alcohol content than is actually present, but neither can indicate a level greater than is actually present. The results of the preliminary breath test that Kenoyer administered to Anderson indicated that his blood alcohol content was greater than .10. Anderson later submitted to Kenoyer’s request for a blood test and the results indicated that Anderson’s blood alcohol content was .25 percent.
Anderson apparently contends that under SDCL 32-23-10 a PBT cannot be given prior to arrest. The statute reads in part:
Any person who operates any vehicle in this state is considered to have given his consent to a chemical analysis of his ... breath ... to determine the amount of alcohol in his blood ... provided the test is administered at the direction of a law enforcement officer having lawfully arrested the person for a violation of SDCL 22-23-1.
Under Anderson’s theory, a law enforcement officer would have to subjectively determine from relevant facts and circumstances that probable cause for arrest ex*891isted under SDCL 32-23-1, the DWI statute, before a PBT could be administered.
A lawful arrest requires that the arresting officer have either an arrest warrant or “reasonable” or “probable” cause to believe the person arrested had committed or was committing a crime. Draper v. United States, 358 U.S. 307, 79 S.Ct. 329, 3 L.Ed.2d 327 (1959). This court examined the requirements for probable cause for arrest in State v. Glick, 87 S.D. 1, 201 N.W.2d 867 (1972), and stated that:
“To establish ‘probable cause’ proof beyond a reasonable doubt is not required. ‘On the other hand, good faith on the part of the arresting officers is not enough. Probable cause exists if the facts and circumstances known to the officer warrant a prudent man in believing that the offense has been committed * * * suspicion is not enough’.”
87 S.D. at 5-6, 201 N.W.2d at 869, citing Henry v. United States, 361 U.S. 98, 80 S.Ct. 168, 4 L.Ed.2d 134.
In State v. Moves Camp, 286 N.W.2d 333 (S.D.1979), this court stated that a police bulletin, or a tip such as the Wall Police Chief’s call to Kenoyer, may constitute probable cause when independent factors, outside the police bulletin or tip, also provide a basis for probable cause. Id. Kenoyer testified that he did not observe Anderson violate any traffic laws prior to the time that he stopped the Scout and that Anderson passed the four physical sobriety tests he administered and that Anderson did not exhibit physical manifestations of being under the influence of alcohol prior to administration of the PBT. By Kenoyer’s admission, the PBT was administered on the basis of the Wall Police Department tip, which, under this court’s standard for probable cause for arrest, is not sufficient on its own, see Moves Camp, supra. However, the odor of alcohol about Anderson and Anderson’s admission that he had consumed alcohol the night before are additional facts which, in this case, constitute probable cause.
The State contends that SDCL 32-23-10, the implied consent law, refers only to tests, the results of which may be admitted as evidence to show alcohol content in relation to SDCL 32-23-7, the presumptive level for conviction under SDCL 32-23-1. This argument is based on the State’s assertion that PBT results are not used as evidence of an alcohol content above or below .10, the presumptive level, but are only used as a pre-arrest sobriety test to establish probable cause for arrest and the administration of evidentiary tests, i.e., the blood test or the intoxilyzer.
The issue is whether preliminary breath alcohol tests, facilitated by portable breath testing devices, may be given on the scene before probable cause for arrest becomes apparent. We believe that SDCL 32-23-10, which permits chemical analysis of a defendant’s blood, breath or other bodily substance after a lawful arrest has been made, must be read in pari materia with the rest of the chapter. SDCL 32-23-10 specifically states that a chemical analysis may be done “to determine the amount of alcohol in his blood as provided in § 32-23-7 ....” SDCL 32-23-7 involves the statutory presumptions attached to different levels of blood or breath alcohol as determined by the chemical analysis permitted under SDCL 32-23-10. Blood and breath test results may indicate a per se violation of SDCL 32-23-1(1) and can be conclusive evidence to show a violation of SDCL 32-23-1(2). Refusal to submit to the chemical analysis permitted under SDCL 32-23-10, the implied consent statute, may result in driver’s license revocation. Consequently, the legislature’s limitation of ev-identiary chemical analysis to arrest situations is appropriate.
Anderson was not under arrest in this case and chemical analysis of his breath cannot be justified under the implied consent law. His license could not have been revoked had he refused to take the PBT and the statutory presumptions provided by SDCL 32-23-1(1) and SDCL 32-23-7 cannot attach to the test results.
SDCL 32-23-1.2 states, however, that:
*892Every person operating a motor vehicle which ... is operated in violation of any of the provisions of this chapter shall, at the request of a law enforcement officer, submit to a breath test to be administered by such officer. If such test indicates that such operator has consumed alcohol, the law enforcement officer may require such operator to submit to a chemical test in the manner set forth in this chapter.
This statute permits a preliminary breath test prior to arrest when a person operates a vehicle in violation of any provision contained in SDCL ch. 32-23.
Anderson contends that law enforcement officers who administer the PBT test must have probable cause to arrest a suspect for violation of a provision of SDCL ch. 32-23 prior to administration of that test under SDCL 32-23-1.2. We disagree.
The legislature would not have gone to the trouble of passing SDCL 32-23-1.2 if they did not intend it to go beyond the restrictions incorporated in SDCL 32-23-10. Probable cause for arrest is not required for administration of the PBT under SDCL 32-23-1.2. A reasonable suspicion on the part of a law enforcement officer that a person is operating a motor vehicle in violation of any of the provisions of SDCL ch. 32-23 is sufficient justification for administration of a PBT.
PBT results may not be used as evidence against a defendant. The statute specifically provides that: “If such test indicates that such operator has consumed alcohol, the law enforcement officer may require such operator to submit to a chemical test in the manner set forth in this chapter.” SDCL 32-23-1.2. The results of the second test may be used as evidence “in the manner set forth” in SDCL ch. 32-23, which includes the statutory presumptions. Refusal to submit to a PBT does not warrant revocation of license; however, refusal to submit to chemical analysis after probable cause is demonstrated through the PBT does warrant license revocation. The PBT results may be admitted as evidence only when a defendant raises the issue of probable cause and questions the grounds for the arrest.
We believe that SDCL 32-23-1.2 permits implementation of the PBT as a field sobriety test, which, like the traditional mental and physical dexterity tests, may be given upon reasonable suspicion that a person has violated SDCL 32-23-1. An officer’s reasonable suspicion that a driver is under the influence of alcohol may include (1) a subjective opinion based on observation and perception,* (2) observation of improper driving, (3) a tip from a reliable source, or (4) an admission of alcohol consumption. In this case, the Wall Police Chiefs tip, the odor of alcohol about Anderson, and Anderson’s admission that he had consumed alcoholic beverages the night before he was stopped, justified Ke-noyer’s reasonable suspicion that Anderson was driving while under the influence.
We reverse the trial court’s order and remand for further proceedings.
FOSHEIM, C.J., WOLLMAN, J., and WUEST, Acting Justice, concur. HENDERSON, J., concurs in result.The odor of alcohol, slurred speech, loss of balance or dexterity or any of a number of other observable factors may be the basis for a subjective opinion.