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Title:

Why is Traffic Congestion Getting Worse? A Quantified Decomposition of Contributors to the Growing Congestion in San Francisco

Accession Number:

01764248

Record Type:

Component

Abstract:

Traffic congestion has worsened noticeably in San Francisco (SF) and other major cities over the past few years. Part of this change could reasonably be explained by strong economic growth or other standard factors such as road and transit network changes. It also corresponds to the emergence of Transportation Network Companies (TNCs), such as Uber and Lyft, raising the question whether the two may be related. The authors' research incrementally decomposes the contributors to increased congestion in SF between 2010 and 2016, namely, road and transit network changes, population growth, employment growth, TNC-volumes, and the effect of TNC pick-ups and drop-offs. The authors do so through a series of controlled travel demand model runs, supplemented with observed TNC-data collected from the Application Programming Interfaces of Uber and Lyft. The authors' results show road and transit network changes over this period have only a small effect on congestion. Socioeconomic factors contribute about a quarter of the congestion increase, and that TNCs are the biggest contributor to growing congestion over this period, contributing about half of the increase in vehicle hours of delay, worsening travel-time reliability. This study is more data rich and spatially detailed than past studies, providing a better understanding of where and when TNCs add to congestion. It gives transportation planners a better understanding of the causes of growing congestion, allowing them to more effectively craft strategies to mitigate or adapt to it.

Supplemental Notes:

This paper was sponsored by TRB committee AED20 Standing Committee on Urban Transportation Data and Information Systems.

Report/Paper Numbers:

TRBAM-21-03020

Language:

English

Corporate Authors:

Transportation Research Board

Authors:

Roy, Sneha
Cooper, Drew
Mucci, Richard
Sana, Bhargava
Chen, Mei
Castiglione, Joe
Erhardt, Gregory

Pagination:

20p

Publication Date:

2021

Conference:

Transportation Research Board 100th Annual Meeting

Location: Washington DC, United States
Date: 2021-1-5 to 2021-1-29
Sponsors: Transportation Research Board; Transportation Research Board

Media Type:

Web

Features:

Figures; References; Tables

Identifier Terms:

Lyft; Uber

Geographic Terms:

San Francisco (California)

Subject Areas:

Highways; Operations and Traffic Management; Planning and Forecasting; Policy

Source Data:

Transportation Research Board Annual Meeting 2021 Paper #TRBAM-21-03020

Files:

TRIS, TRB, ATRI

Created Date:

Dec 23 2020 11:23AM