THE PLT ELECTED TO TAKEOFF TO THE NORTH ON A DOWNSLOPING PAVED ROAD. HE REPORTED THAT THE WIND WAS VARIABLE FROM THE SOUTHWEST AT 2 TO 4 KTS, GUSTING 4 TO 6 KTS. AT AUSTIN, TX, THE WIND WAS FROM 190 DEG AT 13 GUSTING 20 KTS & AT COLLEGE STATION, TX, IT WAS FROM 200 DEG AT 11 KTS. THE SELECTED ROADWAY WAS APPRX 1800 LONG, THEN CURVED TO THE RIGHT. DURING THE TAKEOFF, THE ACFT BECAME AIRBORNE BEFORE REACHING THE CURVE, BUT THE LEFT WING HIT 35 FT TREES ON THE LEFT SIDE OF THE ROAD AFTER LIFT-OFF & THE ACFT CRASHED. ACCORDING TO THE ACFT'S OPERATING HANDBOOK, 1624 FT WAS REQUIRED TO CLEAR A 50 FT OBSTACLE IN NO WIND CONDITIONS. THE PLT STATED THAT HE ENCOUNTERED AN ENG PROBLEM, BUT NO PREIMPACT PART FAILURE OR MALFUNCTION WAS FOUND. THE PLT ALSO STATED THAT HE HAD PREVIOUSLY ENCOUNTERED AN ENG PROBLEM & HAD MADE A PRECAUTIONARY LANDING ON THE ROAD, THEN ELECTED TO TAKEOFF AFTER THE ENG & FUEL CHECKED NORMAL. HOWEVER, WITNESSES TOLD LAW ENFORCEMENT PERSONNEL THAT THE PLT HAD LANDED & PICKED UP THE PASSENGER. SPEED & PROP SLASH MARKS INDICATED 2450 RPM