*666If the documents filed in support and in opposition to the motion for summary judgment forecast evidence, which if offered at trial would entitle the defendant to a directed verdict, the motion for summary j udgment was properly allowed. Moore v. Fieldcrest Mills, Inc., 296 N.C. 467, 251 S.E. 2d 419 (1979). If the only reasonable conclusion the jury could make is that the plaintiff, by driving his motorbike on the defendant’s roadway after dark without a light, did something a reasonable 15-year-old boy would not have done under the circumstances and he should reasonably have seen that he might collide with a cable or something else on the roadway, the plaintiff was contribu-torily negligent as a matter of law. See 9 Strong’s N.C. Index 3d, Negligence §§ 1, 8, and 13 (1977) for definitions of negligence, contributory negligence, and proximate cause. We hold that this is the only reasonable conclusion the jury could make. We believe that at age 15, a person should know that it is dangerous to ride a motorbike at night without lights and that a cable or other object is likely to be on a private roadway which can cause a collision and injury. Summary judgment for defendant was proper.

The plaintiff argues that it could be inferred that he was operating the motorbike at a safe rate of speed; that he was operating it in a prudent manner; that he had it under proper control and used a proper lookout. In answer to these arguments, it was not speed which was the cause of the collision; it was not in a prudent manner to drive without lights; and he could not keep a proper lookout if he did not have a light on the motorbike. Plaintiff also argues that it may be inferred that he could not have seen the cable if it had been daylight or if he had a spotlight on the motorbike. We do not believe we should speculate on either of these hypotheticals. In the case sub judice, the plaintiff was not able to see the cable in the dark. See Starr v. Clapp, 40 N.C. App. 142, 252 S.E. 2d 220 (1979).

Affirmed.