I-25 and I-70.
Probably none are still used as roads. Parts of some are still used as roads and parts are used as tracks or footpaths.
The dealer, EBAY, do a google search..... they are used for roads
The Colorado River is used for rafting and recreation, also you could go swimming in some parts of the Colorado river.
Sidewalks and roads.
Alloys of elemental magnesium are often used to make lightweight luggage and some aircraft; magnesium chloride is often used to deice roads; and magnesium hydroxide is a common antacid/laxative.
Yes they are very strong some of the roads are used today thousands of years later.
A backroad is a secondary road, often through rural areas used as an alternate to main roads.
Roads in the Aztec era were well-kept and often paved. Regular resting places were provided. Since the Aztecs did not know the wheel and did not have draft animals, the roads were used for travel on foot
Some modern roads follow the path of Roman Roads. After the end of the Roman civilization, the stone paving of the Roman Roads was not replicated. However, some Roman Roads remained important trade routes in the Middle Ages and followed trade itineraries which are still used today.
Basalt can be used for making roads
One reason is because northern state's roads are more frequently used by a larger number of people, so repairs are needed more often.
Everyone used the roads. They were built for the military, but everyone used them. The roads were well built and some still exist today. I drove the Appian way in the 1970's, but today it is closed to cars.