Who uses it Contractors. Utility Companies. Public Works Departments. They are all turning to horizontal directional drilling (HDD) as their preferred method of installation or replacement. Reasons include cost-effectiveness, minimization of surface damage, low disruption to traffic or other activities, and environmental friendliness. Where it's used Almost anywhere that surface conditions make it harder and more expensive to operate traditional trenching machinery like backhoes or excavators. This includes tunneling under streets and buildings, under landscaped areas and rivers, or under parking lots and highways among so many other applications