In this appeal we are called upon to determine what constitutes “reasonable grounds to believe that the person [charged with the traffic violation] will disregard [the] traffic citation,” and whether subjecting that person to a warrantless arrest for a traffic violation was illegal.
Willis T. Parker, appellant, having been found guilty in the Circuit Court for Baltimore City of possession of cocaine with intent to distribute, contends on appeal that:
The court erred in denying appellant’s motion to suppress the drugs and money seized from appellant’s pocket and from the car.
We disagree and shall affirm.
Transportation Article, § 26-202(a)(2) (1984 Repl.Vol., 1985 Supp.) provides in pertinent part that:
A police officer may arrest without a warrant a person for a violation of the Maryland Vehicle Law, ... if ... the person has committed or is committing the violation within the view or presence of the officer, and either: (i) the person does not furnish satisfactory evidence of identity; or (ii) the officer has reasonable grounds to believe that the person will disregard a traffic citation.
It was pursuant to subsection (a)(2)(h) that Officer John J. Fabula arrested the appellant on August 29, 1984, after concluding that he was operating a motor vehicle without an operator’s license. Upon a search incident to the arrest, Officer Fabula recovered from the appellant’s right pants pocket a small clear plastic bag with some rice and five *4gelatin capsules containing a white powder which he believed to be cocaine. The officer then conducted a search of the vehicle which the appellant had been operating and recovered a bag which contained a large clear plastic bag with rice and twenty gelatin capsules, again containing a white powder which the officer thought was cocaine. Subsequently, appellant was charged, by criminal information, with possession of cocaine with intent to distribute, and on February 4, 1985, a suppression hearing was held in the Circuit Court for Baltimore City, the Honorable Marshall Levin presiding. At that hearing both Officer Fabula and the appellant gave conflicting testimony concerning the arrest and subsequent search and seizure. For reasons more particularly stated in the record, Judge Levin resolved the conflicts in favor of the police officer. As factfinder, he believed the testimony of Officer Fabula over that of the appellant.
The officer’s testimony revealed that on August 29, 1984, at about 2:50 p.m., in the 700 block of Cumberland Street in Baltimore City, he observed the appellant driving an automobile without a left rear brakelight. He followed and eventually stopped the car. As he approached the vehicle, he observed the appellant nervously and quickly roll a paper bag and place it in the console of the automobile. When he asked the appellant for his driver’s license and registration for the vehicle, the appellant “became somewhat nervous and he exited the car for no reason and walked to the front of the vehicle.” The officer further testified:
He had no reason to exit the car like that. I was surprised when he got out and walked fast like that, and for a moment I thought he was going to run so I quickly walked behind him.
Again, Parker was asked for his license and registration and responded that he should not be driving the vehicle and that he had no driver’s license or registration. When asked for any other identification, he produced a “prison ID which contained his picture but no address.” Appellant continued his nervous behavior, i.e., “he was rubbing his face, and *5walking to the front of the car and repeating, ‘Man, I should not have been driving the car, and all that’s stuff, you know, you got me.’ ” Additionally, the officer thought that the appellant “was on something” — i.e., some type of controlled dangerous substance, because the officer could discern no odor of alcohol, appellant’s eyes were watering, he was talking fast and rubbing his eyes and nose. The officer determined via the police radio that the vehicle was not reported stolen and that the appellant had no driver’s license. He placed him under arrest, initially testifying that:
Because I didn’t think that everything was going together ... as far as his attitude, nervousness, he was placed under arrest for no Maryland driver’s license, the ID part of it.
Further on in the hearing, the officer testified that he thought the appellant might not show up for trial, or that he might run away because of “his attitude, your Honor, the nervousness.” At an even later point in the hearing, Officer Fabula stated that he arrested the appellant because: “I thought he was not going to make the ticket good, your Honor.” When asked by the court why he felt that way, he responded, “Just that one piece of ID, your Honor [the prison card].”
After carefully summing up the testimony and evidence, Judge Levin overruled the motion to suppress, succinctly setting forth his reasons:
So now the question finally is, if I do believe him, was he reasonable when he says that he felt that the defendant would not show up.
Well the defendant, to the officer’s mentality, was driving a car when he had no business driving that car. He did not have a license to drive it.
Number two, he was nervous.
Number three, he did not supply that degree of evidence as to his identity, which includes, I find, his address, to put the officer’s mind at ease.
*6Next that he showed him a card which showed he had been in prison.
Next, that he made a suspicious move of putting a bag and attempting to hide from the officer’s view, a bag.
Now it is true that the officer did not know what the bag had in it, but I find that all of these factors together furnish objective reasonable ground to believe that he would not show up, that he would disregard the traffic citation.
In asserting that the trial judge erred in admitting the evidence, appellant launches a two-pronged attack claiming first, that the arrest was illegal, and second, that even if the arrest was legal, the “inventory search” of the car was illegal.
I. Legality of the Arrest
Appellant contends that the arrest was illegal because it was not based upon a reasonable belief that the appellant would ignore the traffic citation. He argues that an arrest for a minor traffic violation cannot be used as an investigative tool merely because the police officer suspected that everything was not “going together.” What constitutes “reasonable grounds to believe that the person will disregard a traffic citation” has never been interpreted by our appellate courts. In this case of first impression, we have no difficulty in determining the intention of the legislature when it chose those words. We need look no further than the statute itself.
First, we observe that for the more serious offenses, such as driving while intoxicated, driving while under the influence of any drug, failure to stop in the event of an accident and driving on a revoked license, § 26-202(a)(3), a police officer may immediately arrest the alleged offender without regard to concerns of identity or belief that the person will disregard the traffic citation. With that in mind, we observe that the legislature contemplated situations where, in order to enforce less serious traffic laws, it would be *7necessary to insure the appearance of the defendant at trial. Thus, where the person has not furnished satisfactory evidence of identity or where the officer otherwise had reason to believe that the person would disregard the citation, that is, not appear for trial, the officer could arrest on the spot.
Because we have no difficulty in holding that “reasonable grounds to believe” is tantamount to “probable cause” to believe, Graham v. State, 13 Md.App. 171, 177, 282 A.2d 162 (1971), cert, denied, 264 Md. 748 (1972), we may rely on the definition of “probable cause” as the barometer for determining whether Officer Fabula had “reasonable grounds to believe” that the appellant would not appear for trial. “Probable cause has been defined as a non-technical conception of a reasonable ground for a belief of guilt requiring less evidence for such belief than would justify conviction, but more evidence than mere suspicion.” Cuffia v. State, 14 Md.App. 521, 525, 287 A.2d 319 (1972), cert, denied, 265 Md. 736. Its existence, justifying an arrest without a warrant, must be determined by factual and practical considerations of everyday life on which reasonable and prudent persons, not legal technicians, act. 5 Am.Jur.2d, Appeal and Error § 48 (1962). As the Supreme Court said in Brinegar v. United States, 338 U.S. 160, 69 S.Ct. 1302, 93 L.Ed. 1879 (1949), “in dealing with probable cause, ... as the very name implies, we deal with probabilities.” Id. at 175, 69 S.Ct. at 1310. And we note that one definition of the word “probable” is “that which is likely to be so, or more likely to occur than not to occur.” Webster’s New Twentieth Century Dictionary 1433 (Unabridged 2d ed. 1977).
Returning to the definition set forth in Cuffia, we believe that it is fair to say that the establishment of “probable cause” requires more than mere suspicion but less than belief “beyond a reasonable doubt” (the standard for a finding of guilt). Thus, we find ourselves dealing with a standard that perhaps we could characterize as being *8in the middle ground: the belief that what is alleged to have occurred was more likely so than not so.
In the multitude of cases where “probable cause” has been evaluated, courts have dealt with it in the context of whether a police officer had probable cause to believe that a felony or misdemeanor had been or was being committed. It has been said that such determination of
probable cause is not to be evaluated from a remote vantage point of a library, but rather from the viewpoint of a prudent and cautious police officer on the scene at the time of the arrest. The question to be answered is whether such an officer in the particular circumstances, conditioned by his observations and information, and guided by the whole of his police experience, reasonably could have believed that a crime had been committed by the person to be arrested____
Patterson v. United States, 301 A.2d 67, 69 (D.C.1973). See also VonSleichter v. United States, 472 F.2d 1244, 1248 (D.C.Cir.1971); Davis v. United States, 409 F.2d 458, 460 (D.C.Cir.1969), cert. denied, 395 U.S. 949, 89 S.Ct. 2031, 23 L.Ed.2d 469.
Thus, it is apparent that in the usual evaluation of “probable cause,” we are analyzing the officer’s judgment as to something that has either already occurred or is occurring contemporaneously. He must consider that which he sees and hears or has seen and heard, evaluate it, synthesize it, and determine whether criminal activity is occurring or has occurred and whether the person that he would arrest is the perpetrator.1
*9In the instant case, although we still view the circumstances from that of the “prudent and cautious police officer on the scene,” and consider whether the particular circumstances, his observations and information, guided by the whole of his police experience, would reasonably cause him to believe that the offender would not appear, we are dealing here not with suspected past or present criminal activity. Rather, we are dealing with a forecast that the suspect will “probably” fail to appear for trial in the future.
On the question of disregard of the traffic citation, he must ask himself, “Is that more likely to occur than not to occur?” His task is similar to that of a medical doctor making a “prognosis.”2 Quite naturally, his prognostic ability is a reflection of his training, experience and intelligence, all of which contribute to his ability to reason.
Essentially, therefore, we are asked to extend the “reasonable grounds — probable cause doctrine,” which generally is invoked retrospectively, to situations where it is invoked prospectively.
Against that backdrop, we must determine whether the trial judge’s conclusion of reasonableness was correct. We hold that it was and shall explain our reasons.
It is uncontroverted that the appellant committed a traffic violation: driving without an operator’s license, within the view or presence of the officer. Therefore, the only legal question before us to be viewed under our own “independent reflective constitutional judgment,” Dixon v. State, 23 Md.App. 19, 327 A.2d 516 (1974), is, as correctly stated by the trial judge:
*10Whether the officer had reasonable grounds to believe that the appellant would disregard the traffic citation.
Appellant argues here, as he did below, that the purpose of his arrest was not to insure that he would appear for trial, but because the officer suspected something illegal was occurring when the appellant placed the bag into the console and put the lid on the console chamber down. Appellant suggests that the arrest was a subterfuge; that it was an investigative tool because the officer suspected criminal activity.3
Further, the appellant somewhat boldly but obliquely suggests that the court's ruling was not really based on the five “facts” indicated in its oral opinion, but rather on the officer’s suspicion of illegal activity and the possibility in the mind of the officer that the evidence would disappear if he permitted appellant to leave the scene rather than placing him under arrest. The police officer, in response to questioning by the court, stated that he arrested the appellant because he believed that he would not “make good on the ticket.” At this point he was “eyeball to eyeball” with the trial judge. The trial judge had the opportunity to judge his credibility. While the appellant may doubt the officer’s sincerity and credibility as to that statement, we must defer to the trial judge’s findings of fact in that regard. Our duty is to make an independent reflective constitutional judgment when reviewing, as we do here, the trial judge’s conclusions based upon that which he found to be true, i.e., the police officer’s version.
We recognize that:
[Although we give great weight to the findings of the hearing judge as to specific, first-level facts (such as the time that an interrogation began, whether a meal was or was not served, whether a telephone call was requested, etc.) we must make our own independent judgment as to what to make of those facts; we must, in making that *11independent judgment, resolve for ourselves the ultimate, second-level facts....
Walker v. State, 12 Md.App. 684, 694-95, 280 A.2d 260 (1971). See Borgen v. State, 58 Md.App. 61, 79, 472 A.2d 114 (1984); Manalansan v. State, 45 Md.App. 667, 415 A.2d 308 (1980); Fidazzo v. State, 32 Md.App. 590, 363 A.2d 583 (1976); Dixon v. State, 23 Md.App. 19, 327 A.2d 516 (1974); Howell v. State, 18 Md.App. 429, 437, 306 A.2d 554 (1973), rev’d on other grounds, 271 Md. 378, 318 A.2d 189 (1974). See also In Re Anthony F., 293 Md. 146, 152, 442 A.2d 975 (1982); Logue v. State, 282 Md. 625, 630, 386 A.2d 780 (1978). Here the “second-level fact” is the existence or non-existence of reasonable grounds to believe that the appellant would disregard the traffic citation.
The police officer’s version of what occurred and his articulation of their impression upon him are evaluated as “first level facts.” As such, we must give great weight to the findings of the trial judge with respect to these first level facts. As an appellate court, we
can reject the testimony of a witness credited by the triers of the fact only when the testimony is inherently improbable. There must exist a physical impossibility that the statements of the witness are true or their falsity must appear without resorting to inferences or deduction. The appellate court may not substitute its judgment with respect to the credibility of a witness for that of the ... trial judge on the ground that the evidence is inherently improbable unless it is so clearly false and unbelievable that reasonable minds may not differ.
Borgen, supra [58 Md.App.] at 79-80, 472 A.2d 114.
Because Officer Fabula’s testimony was neither inherently improbable nor physically impossible, we must accept the trial court’s findings as to the first level facts.
The concept of first and second level facts arose primarily from “confession” cases in which the ultimate question of voluntariness is one of fact. It has been extended, however, to cases in which the ultimate question is *12one of law — whether an officer’s knowledge sufficed to give him probable cause to make an arrest or conduct a warrant-less search. Although in a literal sense it is probably inappropriate to refer to such a legal conclusion as a “fact” —even a “second level” or “constitutional” fact — the same analysis is employed. We give the trial court deference with respect to the underlying facts — what the officer observed and what his mental state was — but use our own judgment as to whether the legal conclusion drawn by the court from those facts is correct.
Now, in making our own independent judgment as to what to make of those facts, Walker, supra, we must resolve for ourselves the ultimate second level facts of this case — the existence or non-existence of (“reasonable ground”) probable cause to believe that the appellant would not appear for trial. Was the officer justified in determining that it was more likely so than not so that the appellant would fail to appear at trial? We must remember that unlike situations where a police officer is assessing past conduct, as we noted earlier, Officer Fabula was making a prognosis. Based on his experience as a police officer, based on what he saw the appellant do at the scene, he had to “prognosticate” as to whether the appellant would honor the citation. We must remember that the police officer, through his testimony, placed a great deal of weight on the nervous behavior of the appellant. We cannot say that was unreasonable. Likewise, he placed a great deal of weight on the only type of identification presented by the appellant — the prison I.D. card. That this was not a very reassuring piece of identification was not an unreasonable concern of Officer Fabula. The conduct of the appellant in exiting the car in a manner which caused the police officer to believe he.would flee, again, was not an unreasonable consideration on the part of the police officer.
Like other cases involving “probable cause,” what is reasonable turns on the particular facts and evidence presented. The facts must be carefully weighed and sensi*13tively balanced in each case4 so that the constitutional rights of the individual citizen to be free from unwarranted intrusion shall be carefully considered in harmony with the necessity of diminishing the carnage on our highways by fair enforcement of the motor vehicle laws. See Mercer v. State, 6 Md.App. 370, 251 A.2d 387 (1969), cert. denied, 255 Md. 743.
We hold that under the particular facts and circumstances of this case, the arrest was lawful.
The Inventory Search
Appellant asserts that the “so-called inventory search was merely an excuse to discover what was in the paper bag in the console compartment.” The State incorrectly contends that this issue was not preserved. This issue was clearly raised below, but was not expressly ruled upon by the trial judge. We believe, however, that by overruling appellant’s motion to suppress, the trial judge implicitly ruled on the issue, and therefore it is properly before us for appellate review.
*14We hold that the search of the vehicle was legal. Having validly arrested the defendant, Officer Fabula proceeded to make a lawful search incident to the prior lawful arrest. Gustafson v. Florida, 414 U.S. 260, 94 S.Ct. 488, 38 L.Ed.2d 456 (1973); United States v. Robinson, 414 U.S. 218, 94 S.Ct. 467, 38 L.Ed.2d 427 (1973); Jones v. State, 56 Md.App. 101, 122, 466 A.2d 895 (1983). See also R. Gilbert and C. Moylan, Maryland Criminal Law: Practice and Procedure § 29.4 (1983). His observation on the appellant’s person of what he believed to be cocaine thereafter placed the officer in a position where he had the legal right to search the automobile, particularly since he had earlier observed the appellant conceal a bag within the console of that vehicle. Colorado v. Bannister, 449 U.S. 1, 101 S.Ct. 42, 66 L.Ed.2d 1 (1980). See also New York v. Belton, 453 U.S. 454, 455, 461, 101 S.Ct. 2860, 2861, 2864, 69 L.Ed.2d 768 (1981).
JUDGMENT AFFIRMED; APPELLANT TO PAY THE COSTS.
. As stated by one prominent textwriter:
The Supreme Court has made it clear that the expertise and experience of the officer are to be taken into account in applying the Fourth Amendment probable cause test. This is as it should be, for there “would be little merit in securing able, trained men to guard the public peace” if their actions were to be “measured by what might be probable cause to an untrained civilian.”
*9In the usual case, this means that a trained and experienced officer will have probable cause in circumstances when the layman would not.
W. LaFave, Search and Seizure, § 3.2 at 462 (1978) (citations omitted).
. [A] forecast or forecasting; especially, in medicine, a judgment in
advance concerning the probable cause of a disease and the chances of recovery.
Webster’s New Twentieth Century Dictionary, supra at 1438 (emphasis added).
. For an interesting discussion on "Pretext arrest,” see LaFave, Search and Seizure, § 7.5(e).
. In arguing that there were not sufficient reasonable grounds to arrest appellant, appellant cites three cases, each of which we may easily distinguish. In United States v. Thompson, 597 F.2d 187 (9th Cir.1979), the Ninth Circuit held a search of defendant’s person to be unconstitutional, not because it stemmed from an allegedly unlawful arrest, as is asserted here, but because the search violated Terry v. Ohio, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968), and its progeny. In State v. Hehman, 90 Wash.2d 45, 578 P.2d 527 (1978), the defendant had been stopped and had produced a recently expired driver’s license. In holding the custodial arrest to be illegal, the Washington court noted a statutory alternative to arrest, signing a written promise to appear in court, was not given to the defendant. The court, however, said "we do not imply that a law enforcement officer must disregard custodial arrest if he has other reasonable grounds apart from the minor traffic violation itself.” Id., 578 P.2d at 529. Finally, appellant’s cite to State v. Corner, 28 Wash.App. 439, 624 P.2d 204 (1981), is without merit, as the holding there was based on an unreasonable "third search” at the police station after the defendant had been legally arrested.
Here the trial court determined there existed enough factors to constitute "reasonable grounds” to arrest the appellant. Accordingly, there was no error.