You should stay away from alleys, make sure that your prevailing winds will not carry generator fumes to nearby buildings outdoor air intakes.
It happened before, the fumes from the gen set entered the adjacent building OA intakes in the penthouse (with gen set on ground) and triggered the AHU smoke detetctors, resulting into a false alarm and building evacuation.
IBC addresses that since it IS the code for most buildings, NFPA being only a guideline in some jurisdictions.