The pilot reported that before the flight the airplane was fueled with 142.4 gallons of 100 low-lead fuel and that the fuel tanks contained 236 total gallons of fuel before takeoff. The local aerial survey flight was flown at 16,500 ft mean sea level (msl) and lasted about 5 hours. At the end of the survey mission and about 10 miles from the destination airport, the pilot noticed low fuel indications, then both engines experienced a total loss of power. The pilot made a right 90° turn away from the airport and selected a service road for a forced landing. During the landing roll the airplane collided with three vehicles on the road. The airplane also collided with a metal traffic light pole, which resulted in a separation of the right wing and aft fuselage. After the accident the pilot stated that the loss of engine power was due to fuel exhaustion. During the airplane wreckage recovery, about 3 gallons of fuel were drained from the left wing tanks and the right wing tanks were empty. The pilot also stated that he did not complete a detailed fuel burn calculation or a weight and balance calculation for the flight. It is likely that the airplane did not contain 236 gallons of fuel before takeoff, and the pilot was unaware of the actual fuel onboard due to inadequate preflight planning and preflight inspection.