Despite a deficit, Governor Gavin Newsom and legislators managed to award a significant amount of funding for transit operations in the California budget. But the state鈥檚 transit package is nowhere near sufficient to meet the Bay Area鈥檚 . If left unfunded, public transportation systems will need to start making drastic service cuts in a year.
To address transit鈥檚 remaining funding gap, State Senator Scott Wiener introduced , which 黑料传送门is co-sponsoring with , a campaigner for smarter transportation and housing policy in the Bay Area. SB 532 would generate as much as $900 million to avert transit service cuts 鈥嬧嬧 cuts that would keep California from slashing greenhouse gas emissions and providing access to opportunity and economic security. SB 532 would avoid those cuts while making improvements in transit safety, cleanliness, reliability, and seamlessness. would attract more riders, in turn increasing transit鈥檚 financial stability. SB 532 would generate the funds for all these benefits by temporarily raising tolls by $1.50 on seven state-owned bridges in the Bay Area for five years, starting January 2024.
The legislation has provoked significant and discussion about the extent to which the proposed toll increase would have disproportionate and inequitable impacts on low-income drivers. It鈥檚 reasonable to ask: In an already expensive region, is it equitable to charge more for driving?
To better understand the equity implications of SB 532 and to design potential mitigations for low-income drivers, 黑料传送门partnered with , a data platform and technology company, to analyze how people travel in the region. We sought to answer three questions: (1) What are the financial impacts of an increased bridge toll on drivers? (2) Who would benefit from the temporary increase in the bridge toll? (3) Who would be harmed if SB 532 fails?
How We Did the Analysis
To better understand how SB 532 might impact low-income drivers and to ensure that the toll is designed with equity in mind,, we need detailed and current income and demographic information about who鈥檚 driving across the region鈥檚 bridges and who鈥檚 riding transit. This Information is surprisingly difficult to come by.
The Metropolitan Transportation Commission (MTC) collects data about numbers of bridge crossings and toll activations, but it is unable to provide details on the demographics of drivers crossing bridges or on many other aspects of their trips. U.S. Census data can provide insight into the demographics of workers moving around the region, but the data are often outdated, are not specific to bridge crossings, and are focused only on typical work commute trips. trips, especially in the wake of the pandemic, so it鈥檚 important to look beyond commute trips for a complete picture of how SB 532 would impact people. Analyses that rely on U.S. Census data alone, , therefore provide an incomplete picture.
To address this gap in data, 黑料传送门and Replica obtained a detailed, seasonal analysis of person and vehicle movements in the built environment in the Bay Area. Replica builds a 鈥渟ynthetic representation鈥 (a 鈥渞eplica鈥) of real-world movements based on an array of data inputs, including census data, traffic counts, cell phone data, credit card transactions, and other public and private sources. It then ground truths and calibrates the model to ensure accuracy. Although not based on direct survey data, the analysis Replica provides is similar to analyses based on regional travel demand models used by many public agencies for planning and policy purposes. Our analysis also includes Fastrak and toll payment data from the Bay Area Toll Authority (BATA). Together, these data sources provide insights into the benefits and burdens of increasing bridge tolls to save transit and into ways to design the toll collection system to minimize the financial impacts on low-income drivers.
Our Three Key Findings
Our analysis pointed to three surprising findings about who is driving over state-owned Bay Area bridges today and about how a temporary toll increase would impact them.
Finding 1: Bridge drivers tend to be higher income than BART riders, earning, on average, $22,000 more than BART riders. More than 40% of bridge drivers earn more than $150,000 per year.
Bridge drivers are an economically diverse group. More than 40% of drivers crossing state-owned bridges in the Bay Area on a typical weekday between fall 2019 and fall 2022 had household incomes in excess of $150,000 a year. Just 17% had household incomes below $50,000.
Incomes of those crossing bridges have increased in recent years: the median income of drivers rose from $114,000 in fall 2019 to $129,000 in fall 2022 (a rate of growth that slightly exceeded the corresponding increase in the regional during the same period). The overall distribution of driver incomes also shifted higher during this time period, with the share of drivers from households earning more than $150,000 increasing and the share of drivers from households earning less than $100,000 decreasing.
As a whole, income levels of drivers crossing bridges also tended to be higher than those of BART riders. Bay Area Rapid Transit is the transit system serving the largest number of comparable regional trips and a likely major beneficiary of funding from SB 532.
Moreover, BART riders tended to be lower income than Bay Area residents as a whole, while drivers crossing bridges tended to be slightly higher income.
Household Income of Private Automobile Drivers Crossing the Bay Area鈥檚 State-Owned Bridges, Typical Weekday, Fall 2019 and Fall 2022
Just 17% of drivers had household incomes below $50,000. Over the two-year study period, the share of drivers with such incomes decreased, while the share of drivers making at least $150,000 increased.

What鈥檚 surprising is how pronounced the income gap is between bridge drivers and transit riders. Replica data show that people riding BART on a typical fall 2022 weekday had a median income of $107,000 鈥 that鈥檚 $22,000 less than bridge drivers鈥 median income. BART riders were also more likely to come from households earning less than $50,000 a year. What these data points suggest is that SB 532 is fundamentally equitable because it is a wealth transfer from higher-income people to lower-income people.
Household Income of Private Automobile Drivers Crossing the Bay Area鈥檚 State-Owned Bridges (Typical 2022 Fall Weekday), BART Riders (Typical 2022 Fall Weekday), and All Bay Area Households (2021)
Compared with Bay Area residents as a whole, BART riders tend to be lower income while drivers crossing bridges are slightly higher income.

Replica data also show that bridge drivers are highly diverse, but not more so than BART riders or Bay Area residents as a whole. A comparison of racial and ethnic identities of bridge drivers between fall 2019 and fall 2022 shows only minor changes in their racial and ethnic diversity.
Racial and Ethnic Identities of Private Automobile Drivers Crossing the Bay Area鈥檚 State-Owned Bridges (Typical 2022 Fall Weekday), BART Riders (Typical 2022 Fall Weekday), and All Bay Area Households (2021)
Bridge drivers are highly diverse, but not more so than BART riders or Bay Area residents as a whole.

Finding 2: Commute trips make up a relatively small portion of all trips, both by bridge drivers and transit riders. However, the share of people riding BART to get to work is higher than the share of people driving over a bridge to get to work. This finding suggests the continuing importance of BART in supporting access to economic opportunity, in spite of increased remote work.
In addition to providing data on the demographics of drivers crossing bridges, Replica also provides insight into trip purpose and destinations. This information is particularly important because demographic analysis derived purely from census data accounts only for regular commutes to and from jobs 鈥 a relatively small share of the overall traffic on bridges.
People use both bridges and BART for a wide variety of purposes. Notably, as of fall 2022, the number of work trips on BART is significantly higher than work trips using bridges. The former account for 26% or as much as 52% of BART use if a return journey is assumed.
Trip Purpose Based on Destination for Private Auto Drivers Crossing Bridges and BART Riders
BART use for commutes to work is increasing. If reverse trips are assumed, the 26% of trips to work means that 52% of BART trips are work related (home to work and work to home).
Trip Purpose (based on destination) | All Drivers Crossing Bridges | All BART Riders | ||
Fall 2019 | Fall 2022 | Fall 2019 | Fall 2022 | |
Home | 37% | 35% | 36% | 33% |
Work | 24% | 17% | 27% | 26% |
Shop | 13% | 17% | 13% | 14% |
Eat | 9% | 10% | 10% | 8% |
Social | 5% | 7% | 3% | 4% |
Recreation | 4% | 6% | 3% | 4% |
Errands | 4% | 4% | 2% | |