The Interstate Highway System is a different system - entirely controlled-access motorways, with a minimum of 4 lanes, divided, and no at-grade crossings.
I don't think the parent is saying the whole E-road network is the equivalent; just that it provides examples of moving country to country without leaving motorways.
That sounds more similar to the US Numbered Highway system than it is to the Interstate Highway System: https://en.wikipedia.org/wiki/United_States_Numbered_Highway...
The Interstate Highway System is a different system - entirely controlled-access motorways, with a minimum of 4 lanes, divided, and no at-grade crossings.