(Not sure if this should go into the Southeast folder or the International folder)
Are roads in Puerto Rico or the U.S. Virgin Islands part of the U.S. Highway System?
In Puerto Rico they definitely are because there are Interstates designated on a few of them. Don't know about Guam.
i don't think they are part of the US highway system. but they may have designated number on them.
This is my webpage, http//freewebs.com/prroads (http://http//freewebs.com/prroads) which has several pics of PR freeways. Its not quite done yet so its incomplete and a bit lame but its better than .nothing
This site has more info than mine http://www.hawaiihighways.com/Puerto-Rico-page1.html (http://www.hawaiihighways.com/Puerto-Rico-page1.html)
Puerto Rico is not considered a territory, but a "commonwealth". They have some benefits that the other territories do not.
The best way to understand PR's political status is to literally translate the Spanish. It is a "Freely Associated State". US politicians found that term unacceptable, and came up with "commonwealth" in English, which is, of course, confusing relative to the four states that term themselves with the same. Anyway, PR pretty much gets to pick which US laws apply to it and which do not.
PR received a share of the interstate highway funding and, like Alaska, built roads that are not signed as, nor up to the standards of, Interstates. I am also certain that PR receives money in the various transportation bills over the years, the same as a state, which have been used for routes signed as PR routes, just as states get funding for US and state routes.
I do not know if fuel in PR is subject to the federal excise tax. Puerto Ricans do not pay federal income tax, but do pay FICA and the place is a part of the US Customs territory. I assume that the fuel is taxed, but I don't know. There is obviously a PR tax, just like a state.
There are no signed US highways in PR, or in AK or HI for that matter.