Lunar Boom Town/Begillion resource harvesting
Bagillion is a large multinational corporation which harvests readily materials from the regolith. It's primary product is He3 which requires it to move millions upon millions of cubic meters of regolith per year. Naturally, it is more profitable to turn some of the moved material into other products after the He3 is extracted than not.
Slag remaining after materials processing is sintered (heated until it clumps together in a mold) into paving blocks and used to create roads.
Construction is currently under on the equatorial belt highway and the nearside Pole to Pole freeway. These highways are intended to support widespread lunar settlement on generous land grants recently issued by the U.N. Extraterrestial Settltement Agency. The Equatorial Belt Highway is intended to allow solar road trains to follow the sun around the moon as they transport critical cargo.
- Materials Processing for Self Replicating Systems for Earth