There are numerous issues:

• We're completely surrounded by very high-traffic roads, sidewalks, and an alley. (no, really, the sidewalk is used a lot... blocking it is certainly not an option during daylight, and probably not even an option after midnight)
• The alley is the ONLY exit for a parking lot. That parking lot is used by several high-profile commercial tenants, including Dunkin' Doughnuts, and a convenience store that is open 24/7. The 24/7 store in particular makes it difficult to move even at 3am, because there will still be regular traffic through that part of the alley.

• the transition from the sidewalk to the alley-entrance is smooth from a macro perspective — there is no sharp curb. However, the alley ramp pavement is fairly uneven, which means we'll certainly have to put something over it to smooth it out
• There is one speedbump in the alley that we'd have to cross, but it's pretty low. It's probably not much bigger than the surface irregularities that we face at the alley entrance.