The Effect of Transportation Network Companies (TNCs) on Congestion in San Francisco

Congestion in San Francisco has worsened in recent years, with with network average PM peak travel speeds decreasing from 16.7 mph in 2009 to 12.2 mph in 2017 on arterials, and from 31.3 mph to 26.4 mph on freeways, while vehicle hours of delay increased by 63%. During this period, transportation network companies (TNCs) such as Uber and Lyft grew to comprise about 15% of intra-San Francisco vehicle trips by 2016. The observed trend of worsening congestion in San Francisco is contrary to the stated goals of TNCs of reducing congestion in major cities. However, other changes occurred during this time period that also may contribute to congestion. Between 2010 and 2016, San Francisco added 70,000 new residents and 160,000 new jobs, and numerous transportation network changes were also implemented. Using data scraped from the Application Programming Interfaces (APIs) of Uber and Lyft, combined with observed INRIX travel time data, socioeconomic data and transportation network supply data, this research documents the change between 2010 and 2016 in key congestion metrics for San Francisco, including vehicle hours of delay (VHD), vehicle miles traveled (VMT), average speeds, and travel time reliability. It attributes the relative contributions of factors of network change, population change, employment change and TNCs to the observed changes in congestion. Rather than reducing congestion, the authors find that TNCs are the biggest contributor to growing traffic congestion in San Francisco, accounting for 52% of the VHD increase, 47% of the VMT increase, and 55% of the decline in speeds.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee ABE30 Standing Committee on Transportation Issues in Major Cities.
  • Corporate Authors:

    Transportation Research Board

  • Authors:
    • Castiglione, Joseph
    • Roy, Sneha
    • Cooper, Drew
    • Sana, Bhargava
    • Chen, Mei
    • Erhardt, Gregory D
    • ORCID 0000-0001-8133-3381
  • Conference:
  • Date: 2019


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 22p

Subject/Index Terms

Filing Info

  • Accession Number: 01698332
  • Record Type: Publication
  • Report/Paper Numbers: 19-04463
  • Files: TRIS, TRB, ATRI
  • Created Date: Mar 1 2019 3:51PM