I remember seeing an earlier article about this. I've driven by there, not sure how ready those two-lane roads are for that many vehicles. Also somewhat surprised they picked this site vs more industrial somewhere closer to US 1, but I guess it being a last-mile distribution facility means the distance to I-95 is important.
The new last mile facility (same thing they are referring to for this site) on Blanding is working out just fine right there (which is a pretty congested spot in the city) - it generates far less overall traffic than the Kmart that previously occupied the site.
Here is what to expect as far as traffic:
1)Rotating shifts of a few dozen people, largely throughout graveyard hours and early morning hours, and
2) From 6:15 AM - 2:15 PM waves of 12-24 delivery vans every half hour, and
3) Perhaps 1, maybe 2 semi trucks an hour at night and into the morning
As with most warehouse facilities that aren't Costco or Sam's Club, there really isn't much traffic generated. Similar to concerns people have about residential, the concerns are largely unfounded and based on unfamiliarity with the business or use involved. Hopefully my description above alleviates your concerns rather than amplifies them.