Building a road takes around 1 to 2 years per 3 to 4 miles of road being built so it can take 20 years or more to complete several miles of roads.
All those roads that are now built took many years to build and lots of work was involved to build those roads.
Before the road construction can even begin it can take as long as 10 years for the planning, permitting etc to happen.
Building a road is an enormous amount of work and requires a lot of workers and materials and equipment and it can cost millions of dollars to get a road completed from one town to another.
That's why we pay taxes and have tags on our vehicles which help pay for those roads we drive on to be built and maintained.