The Seattle Downtown alley grid was developed over a hundred years ago in the time of the horse of buggy. They are too narrow to handle modern traffic demands or the 24/7 building service and the resident demands of 21st century residential buildings.
SDOT trys to funnel all of the traffic off of the streets and into the alleys, but existing alleys can’t handle it. Alleys become overloaded with hotel and residential parking, taxis, sanitation, 24 hr. deliveries, repairs, moving, and emergency services; and major streets can become blocked with vehicles waiting for access to or from the alleys. This is a safety and quality of life issue.
In addition, the lack of alley setbacks permits construction of multiple buildings right up to the alley edge degrading privacy, air and light and safety for residents. This a severe livability issue, but there is a solution. As you allow permits to build new towers, require more setbacks off of the alley to really handle 21st Century demands.