C172 pilot reported a loss of engine power resulted in an off field landing.

Attributes
ACN	1554154
Time
Date	201806
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	VFR
Component
Aircraft Component	Engine
Person 1
Function	Single Pilot
Qualification	Flight Crew Student
Experience	Flight Crew Last 90 Days 15 Flight Crew Total 52 Flight Crew Type 52
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy Ground Event / Encounter Other / Unknown

Narrative:

I encountered a power loss at 7;500 feet MSL. The engine dropped to 1;000 RPM at full throttle. I then followed through the emergency checklist to check the fuel selector; carburetor heat; and magnetos. None of which restarted the engine. I then proceeded to land on [a highway]. I landed the plane safely. No injuries and no damage to aircraft or property. The aircraft has been thoroughly inspected by certified mechanics and the two possibilities they have been able to come to are failure to switch fuel tanks; or carburetor ice. If I forgot to switch fuel tanks; that could've been prevented by being attentive when following checklists and throughout the flight by checking the fuel selector multiple times. Carburetor ice could've been prevented by being aware of carburetor icing conditions and turning carburetor heat on when noticing engine roughness and leaving it on until the engine is running smoothly and fully.

Original NASA ASRS Text

Title: C172 pilot reported a loss of engine power resulted in an off field landing.

Narrative: I encountered a power loss at 7;500 feet MSL. The engine dropped to 1;000 RPM at full throttle. I then followed through the emergency checklist to check the fuel selector; carburetor heat; and magnetos. None of which restarted the engine. I then proceeded to land on [a highway]. I landed the plane safely. No injuries and no damage to aircraft or property. The aircraft has been thoroughly inspected by certified mechanics and the two possibilities they have been able to come to are failure to switch fuel tanks; or carburetor ice. If I forgot to switch fuel tanks; that could've been prevented by being attentive when following checklists and throughout the flight by checking the fuel selector multiple times. Carburetor ice could've been prevented by being aware of carburetor icing conditions and turning carburetor heat on when noticing engine roughness and leaving it on until the engine is running smoothly and fully.

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.