Canada and the U.S
They are called 'International Borders'
National H'ways stay within the borders of their countries. International H'ways cross borders into and through other countries.
Utah has no international borders.
None, Colorado has no International borders.
international trade
The countries that share international boundaries with Israel are Lebanon, Syria, Jordan, and Egypt.
Denmark ! :)
US and Canada
Yes, trains are allowed to cross international borders as long as the countries involved agree. Amtrak regularly crosses between the United States and Canada, and trains cross regularly from Pakistan to India and back. Many trains cross borders to other countries in Europe and other places around the world.
Borders can change through diplomatic negotiations between countries, wars, treaties, or independence movements. Changes can result in the creation of new borders, shifts in existing borders, or the dissolution of borders altogether. International organizations like the United Nations can also play a role in border changes by mediating disputes between countries.
Brazil borders 10 countries and Russia borders 13 countries.