Urban Spatial Structure and the Potential for Vehicle Miles Traveled Reduction: The Effects of Accessibility to Jobs within and beyond Employment Sub-centers

This research examines the relationship between urban polycentric spatial structure and driving. We identified 46 employment sub-centers in the Los Angeles Combined Statistical Area and calculated access to jobs that are within and beyond these sub-centers. To address potential endogeneity problems, we use access to historically important places and transportation infrastructure in the early 20th century as instrumental variables for job accessibility indices. Our Two-stage Tobit models show that access to jobs is negatively associated with household vehicle miles traveled in this region. Among various accessibility measures, access to jobs outside sub-centers has the largest elasticity (-0.155). We examine the location of places in the top quintile of access to non-centered jobs and find that those locations are often inner ring suburban developments, near the core of the urban area and not far from sub-centers, suggesting that strategies of infill development that fill in the gaps between sub-centers, rather than focusing on already accessible downtowns and large sub-centers, may be the best land use approach to reduce VMT

Effect of New Rail Transit Stations on Income Distribution of Nearby Residential Moves

This project brief summarizes findings from a project aimed at addressing the question of "Is new rail transit associated with displacement of low-income residents in near-rail neighborhoods?" To address this question, the researchers used annual data on household locations and incomes from 1994 to 2012 to examine neighborhood income distributions and the pattern of residential moves by income in Los Angeles rail transit neighborhoods. The Los Angeles metropolitan area presents an ideal study area for analyzing transit-oriented development (TOD) and potential displacement. Since 1990, the Los Angeles Metropolitan Transit Authority (Metro) has opened 93 new rail-transit stations. An additional 17 are under construction.View the NCST Project Webpag

The Walking Renaissance: A Longitudinal Analysis of Walking Travel in the Greater Los Angeles Area, USA

Promoting walking travel is considered important for reducing automobile use and improving public health. Recent U.S. transportation policy has incentivized investments in alternative, more sustainable transportation modes such as walking, bicycling and transit in auto-oriented cities such as Los Angeles. Although many past studies have analyzed changes in walking travel across the U.S., there is little clarity on the drivers of change. We address this gap by conducting a longitudinal analysis of walking travel in the greater Los Angeles area from 2001 to 2009. We use travel diary and household data from regional and national surveys to analyze changes in walking trip shares and rates across our study area. Results show that walking has significantly increased across most of Los Angeles, and that increases in walking trips generally correspond with increases in population, employment, and transit service densities. Estimates from fixed-effects regression analysis generally suggest a positive association between population density and walking, and that higher increases in transit stop density are correlated with increased walking trips to and from transit stops. These findings illustrate how regional planning efforts to pursue a coordinated land use-transit planning strategy can help promote walking in auto-oriented or vehicle adopting cities.The open access fee for this work was funded through the Texas A&M University Open Access to Knowledge (OAK) Fund

Displacement and Commuting in the San Francisco Bay Area and Beyond: An Analysis of the Relationship Between the Housing Crisis, Displacement, and Long Commutes

Caltrans: 65A0674 and US DOT: 69A3551747109We use four data sets to study supercommuting in the San Francisco Bay Area and Central Valley of California. We follow previous research in defining supercommuting as commutes longer than 50 miles or 90 minutes one-way. The San Francisco Bay Area has some of the highest housing costs in the United States, and anecdotal evidence has long suggested that households might move from the Bay Area to Central Valley counties, possibly enduring long commutes if they cannot move their job at the same time. Yet evidence on a link between supercommuting and house prices has been limited by data availability. We use the data first to demonstrate that the supercommute is far from uncommon, with some Central Valley counties having supercommuting rates that approach 10 percent of all county commutes. We use data on household moves, from zip code tabulation area to zip code tabulation area (ZCTA to ZCTA), to examine how supercommuting rates at the ZCTA level are linked to flows of in-migration from the Bay Area into the Central Valley. We find evidence that suggests that ZCTAs with higher in-migration flows from the Bay Area have higher supercommuting rates

Ride-Hailing, Ridesharing, and Transit Ridership: A National Study Using the 2017 National Household Travel Survey

USDOT Grant 69A3551747109Caltrans Grant 65A0674Launched with the promise of \u201ccar-sharing\u201d reducing the need for private vehicle ownership, ridehail/TNC services such as Uber and Lyft have been in competition with transit agencies for riders ever since their emergence - prompting the question whether ridehail is a complement to or a substitute for transit. This study uses person-level data from the 2017 National Household Travel Survey and from a SACOG travel model (\u201cSACOG Replica\u201d) to evaluate the overlap between users of ridehailing (such as Uber and Lyft) and public transit riders, and whether the complementarity between modes varies across space. While usage of both transit and ridehailing is greater within half a mile of frequent rail service than further from stations, it is inconclusive whether the complementarity between modes varies with distance to rail transit. A second specification testing the relationship between transit and the portion of ridehail usage unexplained by demographics and land uses suggests that this association could result from individual preferences rather than the modes themselves being complementary. Further, ridehail trips peak at different hours than transit trips even among users of both modes, suggesting that the two modes serve different types of trips rather than ridehailing solving the transit first/last-mile problem

Commuting During and after COVID-19: The Impact of COVID-19 on Shared Mobility and Extreme Commuting in the Bay Area - Central Valley

USDOT Grant 69A3551747109Caltrans contract 65A0674 TO 64This project looks at the mobility patterns and experience in using alternative modes of transportation for disadvantaged workers during COVID-19 in California\u2019s Bay Area and Central Valley. We use governmental survey data of commuters and traffic data from StreetLight to document mobility patterns of the two distinct regions throughout the pandemic. Our findings from SJCOG\u2019s dibs survey suggests that dibs service affects mode choice by increasing the share of commuters who use carpool / vanpool and decreasing the share of those who drive alone. These gains remained sticky during the Covid-19 pandemic. Survey results also point out that carpool / vanpool programs in this region are used by a rather narrow demographic. This group of workers were also more likely to be deemed \u201cessential\u201d and were less likely to work remotely during the pandemic. Evidence from our COVID-19 and commute analysis provides verification of existing income and occupation disparities in commute flexibility that likely contribute to making people more vulnerable to COVID-19. During the first one and a half years of COVID-19, lower-income, essential natural resource and production workers traveled more are more likely to face higher exposure to COVID-19 at their workplace, while higher-income, office workers were able to travel less and shield themselves

Slow Streets and Dockless Travel: Using a Natural Experiment for Insight into the Role of Supportive Infrastructure on Non-motorized Travel

Caltrans 65A0686 Task Order 071 USDOT Grant 69A3551747114In the early stages of the COVID-19 pandemic, cities across the globe converted street space to non-automobile uses. This project studies four of these slow street programs in the U.S.: in Los Angeles, Portland, Oakland, and San Francisco. In each city, the slow streets (implemented in late spring to early fall 2020) are used as a treatment and compared to non-implemented control groups. The dependent variable is counts of dockless scooter trips passing a mid-block screenline for time periods both before and after slow street implementation. Those dockless scooter counts were obtained from historical data provided by Lime, a dockless scooter provider in each of the study cities. Two methodological approaches were used: differences-in-differences (DID) and panel regression analysis with block fixed effects. For the DID analysis, the researchers used networks of candidate slow streets that were not implemented as the control group. Such control networks were available in Los Angeles, Oakland, and San Francisco. For the panel analysis, they used slow street segments implemented later in the study period as control segments for earlier implemented slow street segments, including fixed effects for blocks and for time periods in the panel regressions. The findings show statistically significant associations between increased dockless scooter trips and slow street implementation in each study city, using both DID and panel analyses. The associations are robust to different specifications. The authors calculate the magnitude of the slow street treatment effect by dividing the estimated treatment effect by a 2019 baseline of dockless trip counts. In the DID analysis, they find that slow street implementation increased dockless scooter trip counts from 22.16% to 74.5%, relative to a 2019 (before slow streets) baseline. In the panel analysis, the increase in dockless trip counts on slow streets ranged from 10.77% to 16.75%, relative to a 2019 baseline

Accessibility to Jobs Outside Employment Sub-Centers Has a Larger Impact on VMT Reduction than Accessibility to Jobs Inside Employment Sub-Centers [Policy Brief]

This policy brief summarizes findings from a study to help close the gap by examining how access to jobs in employment sub-centers influences household VMT, using the five-county Los Angeles Combined Statistical Area as an example

Gentrification Near Rail Transit Areas: A Micro-Data Analysis of Moves Into Los Angeles Metro Rail Station Areas

This report seeks to shed light on this latter concern. It begins with a brief summary of the evidence from prior studies on both rail-related housing price increases and changing composition. It then introduces a newly available data source, which we use to examine the relationship between new rail transit station opening and neighborhood income composition. This report aims to determine whether a rail station opening in Los Angeles County is associated with the share and income composition of residents who move in and out of neighborhoods near that rail station. Specifically, we address the following questions regarding gentrification and its tie to rail transit stations: \u2022 Who moves into rail-station neighborhoods and when? \u2022 Are higher income households growing as a share of station area population relative to lower-income households? \u2022 Do rail stations cause this phenomenon or is this happening regardless of the transit investment? The Los Angeles metropolitan area presents an ideal study area for analyzing transit-oriented development (TOD) and potential displacement. Prior to 1990, Los Angeles had not had any intra-urban rail transit service for decades. Since then, 93 new rail-transit stations (see Figure 1 for map) were opened by the Los Angeles Metropolitan Transit Authority (L.A. Metro) and an additional 17 are currently under construction (Boarnet et al., 2015). This buildout amounts to about half of the U.S. spending on new rail transit (L.A. Metro, 2009). Within L.A. Metro, 21% of its budget from 2005-2040 will go toward rail transit capital and operations expenditures (L.A. Metro, 2009). Concurrently, regional and local plans envision that over half of new housing and employment to occur within a half-mile of a well-serviced transit corridor, including rail (L.A. Metro, 2009; SCAG, 2012)