“Interstates are Federal roads, NOT state roads.”
Actually the States build the interstates highways and they are the property of the state they exist in.
“Interstate highways and their rights of way are owned by the state in which they were built. The last federally owned portion of the Interstate System was the Woodrow Wilson Bridge on the Washington DC Capital Beltway. The new bridge was completed in 2009 and is collectively owned by Virginia and Maryland[50] Maintenance is generally the responsibility of the state department of transportation. However, there are some segments of Interstate owned and maintained by local authorities.”
https://en.wikipedia.org/wiki/Interstate_Highway_System#Financing
“Actually the States build the interstates highways and they are the property of the state they exist in.”
This is easy to see when crossing state lines. A good example is on I-10 when driving west from Texas into New Mexico. Road turns into a goat trail.
Nice omission:
About 70 percent of the construction and maintenance costs of Interstate Highways in the United States have been paid through user fees, primarily the fuel taxes collected by the federal, state, and local governments. To a much lesser extent they have been paid for by tolls collected on toll highways and bridges. The Highway Trust Fund, established by the Highway Revenue Act in 1956, prescribed a three-cent-per-gallon fuel tax, soon increased to 4.5 cents per gallon. Since 1993 the tax has remained at 18.4 cents per gallon.
My point stands. They are Federal highways - maintained by States - States which receive Federal funding for this explicit purpose. Funding source by Federal gas tax.