On March 5, 1998, about 1048 eastern standard time, a Cessna 172N, N8342E, registered to Gateway Aviation Inc., operated as a 14 CFR Part 91 personal flight, reported a partial loss of engine power while on base leg to runway 18 at Titusville, Florida. The pilot made a forced landing to a road (non-suitable terrain) and collided with a wire and crashed. Visual meteorological conditions prevailed and no flight plan was filed. The airplane sustained substantial damage. The private pilot and passenger reported minor injuries. The flight originated from Titusville, about 1 hour 18 minutes before the accident. The pilot stated he requested and was approved for a right base for landing at Titusville. He performed the before landing check, applied carburetor heat and reduced engine power. The engine appeared to sustain an additional loss of power. He increased power, and checked the magnetos with negative results. The airplane would not maintain altitude so he made a forced landing to a road. He observed wires, went below the first set, and the tail of the airplane collided with another set of wires. The airplane nosed over inverted onto the highway. Examination of the airframe, and flight controls revealed no evidence of a precrash mechanical failure or malfunction. Visual examination of the engine assembly, and engine control mechanisms revealed no evidence of an uncontained catastrophic failure.