On June 16, 2014, about 1503 central daylight time, an experimental amateur-built Knauf model RV-7 airplane, N707HK, was substantially damaged when it impacted terrain during a forced landing near Rockwall, Texas. The airline transport pilot was not injured. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 without a flight plan. Day visual meteorological conditions prevailed for the cross-country flight that departed from the Charles W. Baker Airport (2M8), Millington, Tennessee, at 1240, en route to the Rockwall Municipal Airport (F46), Rockwall, Texas.The pilot reported that his preflight planning indicated that the 352 nautical mile (nm) direct flight should have taken about 2 hours 15 minutes, using about 21.6 gallons of fuel. Before departing, he added 14 gallons of fuel to the right wing fuel tank, which nearly topped-off the 21 gallon fuel tank. The left tank was not refueled before departure. The pilot stated that he estimated that the airplane fuel load was about 29 gallons before departure; however, he did not visually confirm or measure the actual amount of fuel in the left wing fuel tank. The pilot reported that his normal fuel-burn schedule would be to utilize fuel from the left wing tank for takeoff, climb-to-cruise altitude, and landing flight phases. Fuel from the right wing tank was used for cruise flight and cruise-descent flight phases. The pilot stated that during the accident flight he selected the right wing fuel tank just before reaching the final cruise altitude of 10,500 feet mean sea level (msl). He reported that he exhausted all available fuel from the right wing fuel tank when the airplane was established in cruise flight near Hot Springs, Arkansas (about 190 nm from the destination airport). He then repositioned the fuel selector to draw fuel from the left fuel tank and continued toward the planned destination. The pilot initiated a cruise-descent when the airplane was about 32 nm from the destination airport. When the airplane was about 10 nm from the destination airport, while descending through 4,000 feet msl, the engine began to run rough and eventually lost total power. With the airport insight, the pilot established best glide airspeed and feathered the propeller in an attempt to extend the airplane's glide. Ultimately, the airplane did not have sufficient altitude to reach the airport and a forced landing was made to a nearby road about 2 miles northeast of the airport. The pilot reported that he had to maneuver the airplane over a row of trees shortly before landing, which reduced the airspeed below best glide speed, and as a result, the airplane landed hard on the road. The airplane bounced and came to rest on its landing gear in a ditch located alongside the road. The right main wing spar sustained substantial damage during the forced landing. Following the accident, a visual inspection, completed by the pilot, established that there was no useable fuel in either wing fuel tank. Additionally, both wing tanks appeared to be undamaged and there was no evidence of a fuel leak. The pilot reported that the airplane was equipped with capacitive fuel sending units in each wing fuel tank; however, since their installation, the fuel sending units had been unreliable in providing accurate fuel levels. The pilot reported that the total loss of engine power experienced during the accident flight was due to fuel exhaustion. Additionally, the pilot stated that the accident could have been prevented had he verified the actual amount of fuel available in both fuel tanks before departing on the flight.