* Urban environment. Lots of deliveries in a short period of time.
* Amazon DH is conveniently located near I-95 for easy access to the city as well as I-695 and surrounding suburbia.
* Traffic actually isn't that bad compared with other urban areas.
https://www.youtube.com/watch?t=1&v=Cds9uQMQAnA
and also the governor of the state wrote an oped about how bad Baltimore city is at being a city:
http://www.baltimoresun.com/news/opinion/bs-ed-hogan-baltimo...
I have lived in Baltimore for over 10 years. The roads are in terrible shape, there are only two streets to get across town and they are jammed 12 hours a day. 95 is under heavy construction and the entry points into the city from 95 no longer support the volume of traffic.
I agree with your points though - something like this would be perfect for the city!