Ride-sharing services are a boon for commuters battling with traffic congestion – but a new study suggests they might be a major contributor to that congestion.
The San Francisco Transportation Authority’s Congestion Management Program has concluded that congestion in the city worsened between 2010 and 2016, with ride-sharing services contributing a massive 55% to that increase.
During the period under review, San Francisco added 70 000 new residents and over 150 000 new jobs, adding more trips to the city’s transportation network, but the emergence of transportation network companies (TNCs) such as Uber and Lyft probably had a bigger effect.
Worldwide, the total number of rides on Uber and Lyft grew from an estimated 190-million in 2014 to over 2-billion by mid-2016. In San Francisco, the San Francisco County Transportation Authority (SFCTA estimated approximately 62-million TNC trips in late 2016, comprising about 15% of all intra-San Francisco vehicle trips and 9% of all intra-San Francisco person trips.
The report concludes that TNCs have an effect on congestion.
When compared to employment and population growth and network capacity shifts (such as for a bus or bicycle lane), TNCs accounted for approximately 50% of the change in congestion in San Francisco between 2010 and 2016, as indicated by three congestion measures: vehicle hours of delay, vehicle miles travelled, and average speeds.
Employment and population growth–encompassing citywide non-TNC driving activity by residents, local and regional workers, and visitors–are primarily responsible for the remainder of the change in congestion.
Daily vehicle hours of delay (VHD) on the roadways studied increased by about 40 000 hours during the study period. The study estimates that TNCs account for 51% of this increase in delay, and for about 25% of the total delay on San Francisco roadways and about 36% of total delay in the downtown core in 2016.
Daily vehicle miles travelled (VMT) on study roadways increased by over 630 000 miles, with TNCs estimated to account for 47% of this increase in VMT, and for about 5% of total VMT on study roadways in 2016.
Average speeds on study roadways declined by about 3,1 miles per hour, with the study estimating that TNCs account for 55% of this decline.