Narrative:

After filling my fuel tanks to max capacity (24 gallons usable) I departed VFR [for a three leg flight]. Total distance is 203 miles and I determined while planning that it would take 2 hours total flight time. After landing uneventfully at ZZZ1 and attending [a local exhibit]; I departed for what I determined would be an approximately 30 minute flight to ZZZ. I looked at the sight gauges for the wing fuel tanks; and it appeared to over 1/3 tank and by my estimation; I should have more than 1 hr of fuel. After departing ZZZ; I was approximately 20 miles to the northwest of ZZZ my engine sputtered and then ran smooth. I at first thought maybe the carburetor had iced and applied carb-heat. The engine smoothed out and then started to die and then start running again. By this time I was approx 12 miles to the northwest of ZZZ; and had the tower frequency there already on my active radio. I called the tower and informed them that my engine had stopped and I was going to land next to the interstate. I landed on an empty highway that was just finished with construction and had not opened yet for public use. It was approx 5 lanes wide and completely clear of people; vehicles; overhead power lines; cables and any debris. I landed uneventfully; uninjured; with no damage to property or plane. After landing; upon inspection; it appeared that the sight gauges for the fuel tanks both showed completely empty. My fuel computer/analyzer showed there to still be 5.2 gallons remaining; which if were true would equate into approx 40 minutes remaining. To prevent this from happening I will not rely on flight-fuel computer or sight gauges. I will also use a 'fuel-dipstick' that will visually verify the actual remaining fuel quantity.

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Original NASA ASRS Text

Title: Carbon Cub pilot reported an off airport landing due to fuel exhaustion.

Narrative: After filling my fuel tanks to max capacity (24 gallons usable) I departed VFR [for a three leg flight]. Total distance is 203 miles and I determined while planning that it would take 2 hours total flight time. After landing uneventfully at ZZZ1 and attending [a local exhibit]; I departed for what I determined would be an approximately 30 minute flight to ZZZ. I looked at the sight gauges for the wing fuel tanks; and it appeared to over 1/3 tank and by my estimation; I should have more than 1 hr of fuel. After departing ZZZ; I was approximately 20 miles to the NW of ZZZ my engine sputtered and then ran smooth. I at first thought maybe the carburetor had iced and applied carb-heat. The engine smoothed out and then started to die and then start running again. By this time I was approx 12 miles to the NW of ZZZ; and had the tower frequency there already on my active radio. I called the tower and informed them that my engine had stopped and I was going to land next to the interstate. I landed on an empty highway that was just finished with construction and had not opened yet for public use. It was approx 5 lanes wide and completely clear of people; vehicles; overhead power lines; cables and any debris. I landed uneventfully; uninjured; with no damage to property or plane. After landing; upon inspection; it appeared that the sight gauges for the fuel tanks both showed completely empty. My fuel computer/analyzer showed there to still be 5.2 Gallons remaining; which if were true would equate into approx 40 minutes remaining. To prevent this from happening I will not rely on flight-fuel computer or sight gauges. I will also use a 'fuel-dipstick' that will visually verify the actual remaining fuel quantity.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.