The pilot reported that the approach and landing were normal; however, during the landing roll as the airplane reached about 2/3 of the way down the runway, he realized he was travelling too fast. He retarded the throttle and applied the brakes, and became concerned that the airplane would not be able to stop in time. He decided to initiate a turn onto the taxiway rather than allow the airplane to pass beyond the runway end and down a steep hill. The pilot was unable to complete the turn and the left wing and firewall were substantially damaged when the airplane struck a fence. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.