Opinion by
Mr. Chief Justice Bell,Plaintiff was seriously injured while riding a roller coaster in an amusement park owned and operated by defendant. He brought an action of trespass against *60defendant and a jury found a verdict in his favor in the amount of $75,000.
Defendant asks for judgment non obstante veredicto, which the Court below had denied. It is, of course, hornbook law that the evidence must be considered in the light most favorable to the verdict winner, and he must be given the benefit of every reasonable inference of fact arising therefrom, but he is not entitled to inferences which amount merely to a guess or conjecture: Bohner v. Eastern Express, Inc., 405 Pa. 463, 466, 469, 175 A. 2d 864.
The evidence may be thus summarized:
On August 19, 1956, plaintiff got into a roller coaster car with his wife and two daughters and his cousin and her husband. The car was equipped with individual seat belts and a large handrail to enable a passenger to hold on if he desired. Plaintiff sat in the front seat with his wife and one daughter; the other daughter sat with his cousin and her husband in the rear seat in the same car.
Plaintiff thus described how and what happened: “[After the train] went down the first hill and up [and down] another hill ... I was becoming concerned about my daughter and I looked over to see how she was standing the ride, and then when I went to straighten my head up, it just seemed to ‘freeze’ in that position and then just out of the clear blue sky, we were on this bend and I was thrown up again’ the side of the car and my wife and child was slammed over again’ me and ... it was at that point that I felt my neck snap, and then this tremendous headache, just momentarily started, and the next thing I knew, we were getting off the car. . . .”
Plaintiff never saw or noticed this bend in the course,* although his family did. When he got off *61the roller coaster he sat for about 10 minutes and then walked over 200 yards to his wife’s car and drove it back to meet her in the picnic area. She then drove him to the Veterans Club about 40 miles away and left him there. From the Veterans Club he went to the Eagles Club about ten-thirty, to look for his brother and to pick up his own car, intending to drive home. At the Eagles Club, he had difficulty in “navigating,” experienced strange sensations in his feet and had great difficulty dancing. Two hours later he decided to go home, but when he went outside to the porch he collapsed. He spent the rest of the night on the porch, and about 7:30 a.m., a policeman saw him and took him to Franklin Hospital. He was examined there by Dr. Butters, who diagnosed his condition as polio and sent him to the Lakeside Hospital, a polio hospital at Erie, Pennsylvania. Several hours later he was taken by ambulance to the Hamot Hospital at Erie, where he remained for approximately two months. He was then taken by ambulance to the Veterans Hospital in Pittsburgh.
A neurosurgeon, Dr. Murl E. Final, operated on plaintiff’s neck and testified that plaintiff is now permanently paralyzed in his lower body and this paralysis is, in his opinion, the result of the injuries plaintiff sustained in the roller coaster.
It is well settled (1) that defendant is not an insurer: Cooper v. Pittsburgh, 390 Pa. 534, 136 A. 2d 463, and cases cited therein; Haugh v. Harris Bros. Amusement Co., 315 Pa. 90, 172 A. 145; Schentzel v. Philadelphia National League Club, 173 Pa. Superior Ct. 179, 96 A. 2d 181, and (2) that plaintiff must prove by a fair preponderance of the evidence, (a) that defendant was negligent, and (b) that its negligence was the proximate cause of the accident: Markle v. Robert Hall Clothes, 411 Pa. 282, 191 A. 2d 374; *62Zilka v. Sanctis Const. Co., 409 Pa. 396, 186 A. 2d 897; Bohner v. Eastern Express, Inc., 405 Pa., supra. Moreover, a verdict will not be sustained which is based on conjecture or surmise or guess: Steiner v. Pittsburgh Railways Co., 415 Pa. 549, 204 A. 2d 254; Robbins v. Kaufman, 415 Pa. 192, 202 A. 2d 826.
As the Court relevantly and correctly said in Schentzel v. Philadelphia National League Club, 173 Pa. Superior Ct., supra (page 183) :
“. . -.- ‘One who maintains a “place of amusement for which admission is charged, is not an insurer, but must use reasonable care in the construction, maintenance and management of it, having regard to the character of the exhibitions given and the customary conduct of patrons invited:” Haugh v. Harris Bros. Am. Co., 315 Pa. 90, 172 A. 145.’ Kallish v. American Base Ball Club of Philadelphia, 138 Pa. Superior Ct. 602, 603, 10 A. 2d 831.”
When we apply this test to the facts in the instant case, it means that plaintiff must prove by a fair preponderance of evidence that defendant failed to exercise reasonable care in the erection- or maintenance of its roller coaster track (or its cars and equipment) commensurate with the risk involved.
Plaintiff produced one witness to prove this crucial point of causal negligence. Dr. James Romualdi, an Associate Professor of Civil Engineering at Carnegie Institute of Technology, was plaintiff’s witness. He examined the construction plans of the track and physically inspected it for 20-25 minutes during the trial, nearly six years after the accident. Cf. Murray v, Siegal, 413 Pa. 23, 29, 195 A. 2d 790. He testified (a)- in general as to the engineering principles involved and (b): in particular that “with respect to the design and construction of the track itself there was a very serious violation of good, sound engineering *63design features” in that the track was not adequately banked.*
Dr. Bomualdi based his opinion and conclusions as to the allegedly improper construction of the curve where the accident occurred, upon the proper construction of a railroad or highway which has a completely different design. The construction of curves on a highway for automobiles traveling from 40 to 75 miles an hour is, as Dr. Bomualdi testified, obviously and unquestionably different from the proper construction of a curve on a roller coaster track. It is clear that this was not an applicable analogy. Far more important, Bomualdi’s testimony was inadequate to sustain a finding of negligent construction. Bomualdi had had no experience in designing wooden structures like this, nor had he analyzed them or examined them before trial. He testified (a) that the lateral acceleration was excessive, but he did not “have knowledge of just how much lateral acceleration a person could take”; and (b) twice in his testimony he refused to say that the design was unsafe, but merely said that it was not the best possible engineering design. However, the evidence showed that from the time the track had been reconstructed several months prior to the accident and until the time of this trial, 1,297,802 “human bodies” (persons) (including all of plaintiffs family) had ridden this course and absorbed the abruptness of this curve without injury. In addition to all of this, (a) plaintiff was riding in a safely hand-railed car with seat belts, and (b) admittedly failed to protect himself by holding on (if necessary) to the front rail of the car, and (c) (we repeat) none of *64plaintiffs party or any other person on this ride was injured at this curve or bend on this ride, and (d) plaintiff never told his first doctor (Dr. Butters) of this alleged accident on the roller coaster, and (e) plaintiff never commenced this suit or reported his accident to the defendant or presented a claim to the defendant until a few days before the expiration of the two year statute of limitations.
A majority of the Court are of the opinion that plaintiff, because of the lack of definiteness, positiveness and certainty in the testimony of his expert, failed to satisfy his burden of proving defendant’s negligence, and for this reason* judgment non obstante veredicto must be entered in favor of defendant: Bohner v. Eastern Express, Inc., 405 Pa., supra; Mrahunec v. Fausti, 385 Pa. 64, 121 A. 2d 878; Wagner v. Somerset Co. Mem. Park, Inc., 372 Pa. 338, 93 A. 2d 440.
Judgment reversed and judgment non obstante veredicto entered for defendant.
*65Mr. Justice Cohen concurred in the result. Mr. Justice Eagen dissents.Probably because he turned his head to loot at his daughter at that crucial moment.
As was tó be expected, the defendant produced five ' experts (three of whom were builders or operators of roller coaster tracks) who testified that the track was constructed in accordance with good engineering practice and that the roller coaster course was safe.
The writer of this Opinion would prefer to enter a judgment non obstante veredicto for defendant because of plaintiff’s voluntary assumption of risk. A' joyous, anticipated, jolting, jarring, bumping and violently careening ride on a roller coaster which flings you from side to side is well known to every American boy, girl and man, and is one of our most pleasant memories. It is clear as crystal that plaintiff voluntarily and with full knowledge assumed the dangers of the ride and the risk of injury by being flung from side to side, when he rode this roller coaster. In Schentzel v. Philadelphia National League Club, 173 Pa. Superior Ct., supra (page 186) the Court pertinently stated: “We quote at length from Prosser on Torts at pages 383-384: ‘By entering freely and voluntarily into any relation or situation which presents obvious danger, the plaintiff may be taken to accept it, and to agree that he will look out for himself, and relieve the defendant of responsibility. Those who participate or sit as spectators at sports and amusements assume all the obvious risks of being hurt by roller coasters, flying balls, . . .’ ”. Accord: Douglas v. Converse, 248 Pa. 232, 93 A. 955; Repyneck v. Tarantino, 415 Pa. 92, 202 A. 2d 105.