Like many\ncongested cities, Seattle has experienced a rapid increase in ride-hailing\ntrips by transportation network companies (TNCs) such as Uber and Lyft. That\nincrease has raised broad concerns about congestion, safety, and effective curb\nuse. In response, this study looked at a strategy to manage TNC driver stops and\nimprove traffic flow when passengers are picked up and dropped off in the South\nLake Union area of Seattle.<\/p>\n\n\n\n
Nationally,\nthe share of Americans who use ride-hailing services has more than doubled since\n2015, from 15 percent to 36 percent. In some areas of Seattle, TNC ridership\nhas grown by more than five times its level in 2015. On-line retailer Amazon,\nwhose main campus in South Lake Union has over 8,500 employees, was specifically\nconcerned about the scarcity of curb space where TNC drivers could legally and\nreadily stop. <\/p>\n\n\n\n
To mitigate the impacts of passenger pick-up\/drop-off activity on traffic, the city proposed a strategy of increasing passenger loading zone (PLZ) spaces in South Lake Union, while Uber and Lyft would implement a geofence to direct their drivers and passengers to designated load and unload locations. The rationale was that by providing ample designated pick-up and drop-off space along the curb, TNC drivers would reduce the frequency with which they stopped in the travel lane, as well as they time they remained stopped.<\/p>\n\n\n\n
For this\nstudy, researchers at the University of Washington\u2019s Urban Freight Lab and\nSustainable Transportation Lab analyzed an array of data on streets and curb\nactivity along three block-faces on Boren Ave N in December 2018 and January\n2019. The research team collected data during the morning and afternoon peak\ntravel times by using video and sensor technology, as well as in-person\nobservations. They also surveyed TNC passengers. They collected data in three stages: a study\nbaseline before PLZs had been added; after the new PLZs were added, expanding\ntotal PLZ curb length from 20 feet to 274 feet; and after geofencing was added.<\/p>\n\n\n\n
The study\nfound that passenger loading and unloading made up a significant share of total\nvehicle activity in the study area. Without dedicated load\/unload curb space,\nTNC vehicles stopped and waited at paid parking spots and in other unauthorized\ncurb spots. A significant percentage of\nvehicles also stopped in the travel lane, potentially blocking or slowing\ntraffic. <\/p>\n\n\n\n
Adding PLZs\nand geofencing was found to increase driver compliance in stopping at the curb\nversus stopping in the travel lane to load\/unload passengers. Adding PLZs and\ngeofencing also reduced the average amount of time drivers stopped to load\/unload\npassengers. While curb occupancy increased after PLZs were added, occupancy\nresults showed that the allocation of PLZ spaces was more than necessary to\nmeet observed demand, as average PLZ occupancy remained under 20 percent after\nexpansion, even during commute hours. In addition, adding PLZs and geofencing\ndid not have a significant impact on traffic safety, and it did not produce a\nsignificant impact on roadway travel speed.<\/p>\n\n\n\n
Although the\nstudy showed the approach to be successful in meeting its goals of increasing\ndriver compliance and improving traffic flow, the authors noted that the\nstrategy is not a silver bullet for solving traffic congestion. Any initiative\nto manage use of curbs and roads (by TNCs or others) must be part of a city\u2019s\nbroader transportation policy framework and goals.<\/p>\n\n\n\n