The Supply Chain and Transportation Logistics (SCTL) Center at the University of Washington conducted an alley inventory and truck load\/unload occupancy study for the City of Seattle. The findings allowed the researchers to develop alley management recommendations to promote safe, sustainable, and efficient goods delivery and pick-up.<\/p>\n\n\n\n
Researchers collected\ndata identifying the locations and infrastructure characteristics of alleys\nwithin Seattle\u2019s One Center City planning area. That planning area includes the\ndowntown, uptown, South Lake Union, Capitol Hill, and First Hill urban centers.\nThe resulting alley database includes GIS coordinates for both ends of each alley,\ngeometric and traffic attributes, and photos. Researchers also observed all\ntruck load\/unload activity in selected alleys to determine minutes vacant and\nminutes occupied by trucks, vans, passenger vehicles, and cargo bikes. <\/p>\n\n\n\n
A key finding of this study was that more than 90 percent of Center City alleys are only one lane wide. This creates an upper limit on alley parking capacity, as each alley can functionally hold only one or two vehicles at a time. Because there is no passing room, when a truck, van, or car parks, it blocks all other vehicles from using the alley. When commercial vehicle drivers see that an alley is blocked, they will not enter it, as Seattle Municipal code prohibits backing out of (or into) an alley.<\/p>\n\n\n\n
Another key finding was\nthat 68 percent of vehicles parked in an alley for 15 minutes or less.\nTherefore, the researchers concluded that moving vehicles through alleys in\nshort time increments is the only reasonable way to increase their productivity.\nBecause one parked vehicle operationally blocks an entire alley, the goal of\nnew alley policies and strategies should be to reduce the amount of time that alleys\nare blocked to additional users. <\/p>\n\n\n\n
Additional key findings\nincluded the following:<\/p>\n\n\n\n
In the\nseven alleys studied, 87 percent of all vehicles parked for 30 minutes or less.\nGiven the imperative to move alley traffic quickly, vehicles that need more\nparking time must be moved out of alleys and to the curb.<\/p>\n\n\n\n
The pavement\ncondition of 15 percent of the alleys was found to be so poor that delivery\nworkers cannot traverse them with loaded handcarts. Although trucks can pass\nover uneven pavement without difficulty, delivery people walking with fully\nloaded handcarts cannot. The alley pavements were rated by qualitative\nvisual inspection to identify obvious problems; more detailed measurements\nwould be needed to fully assess conditions.<\/p>\n\n\n\n
Entrances\nto passenger parking facilities were found in 73 percent of Center City area\nalleys. Placing garage entrances in alleys has long been a city policy goal. However,\nthat increases car traffic in alleys. Understanding why cars queue for garage\nspace located off alleys, and providing incentives and disincentives to reduce those\nqueues, would help make alleys more productive.<\/p>\n\n\n\n
Alleys were\nfound to be vacant about half of the time during the business day. While this\nsuggests ample capacity, the fact that an alley can hold only one to two parked\ntrucks at a time means that alleys are operationally limited and therefore not\na viable alternative to the use of commercial vehicle loading zones on city\nstreets.<\/p>\n\n\n\n
The findings indicated\nthat, because of fixed alley width constraints, load\/unload space inside\nSeattle\u2019s existing Center City area alleys is insufficient to meet additional\nfuture demand. <\/p>\n\n\n\n