City Code prohibits the blocking of sidewalks.
10.12.101: STOPPING, STANDING OR PARKING IN SPECIFIED PLACES:
http://sterlingcodifiers.com/codebook/index.php?book_id=855&chapter_id=62852#s1262776
No person shall stop, stand or park a vehicle except when necessary to avoid conflict with other traffic, vehicular or pedestrian, or in compliance with directions of a police officer or traffic control device on a sidewalk or pedestrian walking area.