Principal problem in construction site in urbans areas?

Question:

Answers:
It depends on how urban the area is. New York City is much different than a small urban area.

In NYC I would have to say site logistics. Lack of storage space for materials creates a need for a detailed delivery schedule.

Things can only be delivered to the site as necessary. If they are delivered to fast, there's a backup of material and no place to put it. If they are delivered to slowly, production will halt.