This Borg-like 3-D printer takes an 8-foot step forward every 12 minutes leaving behind the highway of the future. This translates to about a mile a week or 50 miles a year.
The function of the printer is similar to that of an assembly line where the manufacturing process is accomplished as one continuous flow.
The printer is designed so that it can go around corners and navigate hills. The only reason why it is shown here perfectly straight is because of the difficulties involved with creating such a complicated drawing.
For urban installations the 3-D printer can step through the city with minimal disruption to traffic. When crossing sensitive natural environments, the mechanism can pass through with little or no damage save for the posts that hold up the rail.