This is an appeal from a judgment of sentence entered in the Court of Common Pleas of Allegheny County. We reverse.

Appellant Alan Jay Ward was found guilty of violating 75' Pa.C.S. § 3367, Racing on the Highways, before District Justice Lee Peglow. A trial de novo was held before the Honorable Raymond Scheib. Judge Scheib found Ward guilty, and sentenced him to pay a fine of $210.00. Post-trial motions were filed and denied, and this appeal followed. Ward raises two issues for our review:

(1) Whether the court erred in finding the defendant guilty of violating 75 Pa.C.S. § 3367 in that the statute specifically criminalizes driving conduct that is competitive or exhibitionary in nature and no evidence was presented that would show involvement by other parties required by nature to meet the competition or exhibition parameters of the statute?

(2) Whether the Commonwealth presented evidence which was sufficient to prove beyond a reasonable doubt that *543Alan J. Ward was guilty of a violation of 75 Pa.C.S. § 3367?

At trial, Officer John O’Shea testified that on February 28, 1988, he observed Ward driving a 1972 Oldsmobile coupe. Officer O’Shea watched as Ward exited a parking space in the parking lot of the Foodland Shopping Center. Ward backed his vehicle out of the parking space. Officer O’Shea stated that Ward’s acceleration caused his tires to squeal. Ward then stopped at a stop sign, and entered onto the eastbound lane of Route 30. Officer O’Shea testified that as Ward proceeded eastbound on Route 30, he again made a loud squealing sound with his tires. Officer O’Shea pursued Ward, stopped him approximately a mile and a half down the road, and issued Ward a citation for racing on the highway. 75 Pa.C.S. § 3367.

Ward testified on his own behalf. He stated that when he pulled out from the parking lot onto the street, that his “tires might have spun in the gravel[,]” and that there was “an excessive amount of gravel in the parking lot,” which caused his tires to spin.

Section 3367(b) of the Vehicle Code provides:

No person shall drive a vehicle on a highway in any race, speed competition or contest, drag race or acceleration contest, test of physical endurance, exhibition of speed or acceleration, or for the purpose of making a speed record, and no person shall in any manner participate in any such race, competition, contest, test or exhibition.

75 Pa.C.S. § 3367(b) (emphasis added). Ward argues on appeal that because there was no other car involved, his conduct does not fall within the meaning of the statute. The Commonwealth argues that Ward’s conduct falls within the statutory prohibition of driving a vehicle on a highway in any “exhibition of speed or acceleration[.]” 75 Pa.C.S. § 3367(b).

We must first determine whether the rapid acceleration of an automobile on the highway in such a manner as to cause the tires to spin and squeal constitutes an “exhibition *544of speed or acceleration” in violation of section 3367(b) of the Motor Vehicle Code. Our review of the case law in Pennsylvania fails to disclose any court decision holding this type of conduct to be in violation of section 3367. Rather, our research has disclosed that each case pertaining to a prosecution under section 3367 involved at least two motor vehicles, and fell within the statutory prohibitions against “racing” or “drag racing.” See, e.g., Commonwealth v. Frye, 357 Pa.Super. 395, 516 A.2d 38 (1986); Commonwealth v. Honeycutt, 227 Pa.Super. 265, 323 A.2d 775 (1974); Commonwealth v. Miller, 197 Pa.Super. 315, 179 A.2d 251 (1962); Anen Motor Vehicle Operator’s License Case, 194 Pa.Super. 379, 169 A.2d 600 (1961); Commonwealth v. Root, 191 Pa.Super. 238, 156 A.2d 895 (1959); Commonwealth v. Looser, 191 Pa.Super. 254, 156 A.2d 905 (1959); Commonwealth v. Levin, 184 Pa.Super. 436, 135 A.2d 764 (1957). In each of these cases, speed competition was a basic element.

Although there has long been legislation directed against speeding or reckless driving, statutes specifically aimed at racing, or drag racing, are of later origin. See generally 71 Am.Jur.2d, Automobiles and Highway Traffic § 323. In defining the illegal activity isolated by the anti-racing statutes, both the statutes and the courts have tended to use the terms “race” and “drag race” without careful distinction, apparently taking the view that any “speed competition” on the highways or public streets was the essence of the unnecessarily dangerous activity which was sought to be proscribed. Id.; Commonwealth v. Honeycutt, 227 Pa.Super. 265, 323 A.2d 775 (1974).1

This does not mean, however, that the statute prohibits only competitive conduct. Though the statute is primarily aimed at competitive racing, alternative language *545in the statute is directed to exhibitions of speed or acceleration. These alternative offenses do not require more than one driver. The language of the statute clearly prohibits a person from driving a vehicle on a highway in any “exhibition of speed or acceleration.” 75 Pa.C.S. § 3367(b). Therefore, the absence of the element of competition in this clause does not necessarily remove Ward’s conduct from the parameters of the statute. Thus, we cannot agree with Ward's argument that his conduct does not fall within the prohibitions of the statute simply because he was not competing with another driver. See Commonwealth v. Hill, 236 Pa.Super. 572, 346 A.2d 314 (1975), affirmed in part, vacated in part, 481 Pa. 37, 391 A.2d 1303 (1978) (statute must be construed to give effect to all of its language).

Ward also argues that his conduct does not fall within the statute’s prohibition against exhibitions of speed or acceleration because there was no indication “that there was a crowd for which [he] was performing.” The statute does not define “exhibition,” nor do the few cases which have interpreted this statute. Webster’s New International Dictionary, 3d edition, defines exhibition as “an act or instance of showing, evincing, or showing off; a public show or showing.” Ward argues that the statute encompasses only those situations where the individual purposefully gathers an audience to observe his conduct. We disagree.

The purpose of section 3367 is to ensure highway safety.2 It is common knowledge that the deliberate screeching of tires produces tension, which may increase nervousness in *546drivers and pedestrians, thereby increasing the likelihood of an accident. See Beneficial Consumer Discount Co. v. Savoy, 291 Pa.Super. 469, 436 A.2d 687 (1981) (judicial notice may be taken of matters of common knowledge of facts which are so well known that they are incontestable); see also People v. Grier, 38 Cal.Rptr. 11, 226 Cal.App.2d 360 (1964) (court upheld defendant’s conviction for exhibition of speed or acceleration under a similar statute, stating that a particular audience to such an exhibition was not required under the statute, and taking judicial notice of the fact that screeching tires produces tension in drivers). In our opinion, to require the Commonwealth to prove that an audience or crowd was deliberately assembled would frustrate the purpose of the statute. It is precisely those drivers or pedestrians who do not anticipate such an exhibition who are most affected by it. Thus, we find that Ward’s argument that the statute prohibits this conduct only when an audience is purposefully assembled, is merit-less.

In his second issue, Ward claims that the Commonwealth’s evidence was insufficient to prove his guilt beyond *547a reasonable doubt. Our standard of review is well established. We must view the evidence in the light most favorable to the Commonwealth, as verdict winner, and, drawing all reasonable inferences therefrom favorable to the Commonwealth, determine if the evidence is sufficient to enable the trier of fact to find every element of the crime beyond a reasonable doubt. Commonwealth v. Griscavage, 512 Pa. 540, 543, 517 A.2d 1256, 1257 (1986). Moreover, when determining the credibility of witnesses and the weight to be afforded the evidence, the trier of fact is free to believe all, part, or none of the evidence. Id. It is only where the evidence is so inconsistent and unreliable, such that the verdict is based upon conjecture, that the verdict will be overturned. Commonwealth v. King, 287 Pa.Super. 105, 429 A.2d 1121 (1981).

The evidence indicates that this incident occurred as Ward left a shopping center parking lot and turned onto a public highway. Shoppers were in the parking lot area and the parking lot was three quarters full. Officer O’Shea testified that he heard tires squealing, and his attention was drawn to Ward, who was backing out of his parking space in the shopping center parking lot. Officer O’Shea testified that Ward stopped at the stop sign at the parking lot exit and proceeded onto Route 30, at which time Ward’s tires squealed again. Officer O’Shea pointed out that “[a]t the time of the incident there [were] a few other vehicles on Route 30 ... It wasn’t a congested time of day.”

Viewing the evidence in the light most favorable to the Commonwealth, and drawing all reasonable inferences therefrom, we conclude that the evidence was insufficient to support Ward’s conviction of the offense of exhibition of speed or acceleration. Spinning or squealing tires alone is insufficient to support a conviction under this statute. The record is devoid of any evidence other than the fact that Ward’s tires squealed. There is nothing in the record indicating rapid acceleration, or speed in a short distance travelled. Squealing tires alone does not necessarily lead to the conclusion that one is exhibiting speed or acceleration. *548Moreover, we point out that road conditions, especially a loose gravel paving, or tire conditions, may cause inadvertent squealing. We conclude that evidence of spinning or squealing tires, without more, is insufficient to support a conviction under this statute.3

Reversed.