Yes, the U.S. government can build roads through private property using eminent domain — the constitutional power to take private property for public use with just compensation.
Fifth Amendment: "...nor shall private property be taken for public use, without just compensation." Applies to federal, state, and local governments (via Fourteenth Amendment incorporation).
Traditionally: roads, schools, parks, utilities, military bases.
Kelo v. City of New London (2005): Supreme Court ruled economic development qualifies as public use — controversial, prompted 40+ state legislative reforms restricting this interpretation.
Fair market value + potentially: relocation costs, business goodwill, severance damages (value loss to remainder), attorney/appraisal fees (varies by state). Not: sentimental value, subjective worth.
Construction easements, access roads, staging areas — temporary occupation with compensation for duration. Property returns to owner after project.
Eminent domain is real, constrained, and litigated. Road projects invoke it routinely. Owners have procedural protections but rarely prevent the taking itself.