A Technical Assessment of SPUR's "Bumper to Bumper" Report
Committee for Affordable Bay Area Transit
In September 2026, SPUR and engineering contractor Jacobs released Bumper to Bumper, predicting traffic gridlock if voters reject Measure RTM ($1.2B/year) and San Francisco Prop H ($170M/year). This comprehensive technical evaluation reconstructs the underlying math using official October 2025 ridership data, revealing arbitrary assumptions, cherry-picked station lists, undisclosed campaign ties and viable alternatives that were never analyzed.
"Overall, the SPUR analysis is an agenda-driven static analysis filled with advocacy and exaggerations. There are critical omissions – most notably a lack of sensitivity and alternatives analysis. It is unhelpful and misleading in predicting the impacts from the potential service cuts, and thus doesn't make a good case in favor of the transit tax. Rather, the conclusion was already known at the outset."— Professor Damian Park, Santa Clara University, Economics Dept. (Email, October 3, 2026)
Key findings from the reconstruction of SPUR's calculations using official agency data.
SPUR projected $174 million in annual driving expenses for shifted riders, but Measure RTM and SF Prop H extract roughly $1.37 billion per year in new taxes. Adopting the sales taxes costs Bay Area residents $1.2 billion more per year than not adopting them.
Across seven major Bay Area transit agencies between 2019 and 2024, passenger-miles fell 51% while operating expenses rose 27%. Instead of rightsizing operations, the cost of carrying one rider one mile skyrocketed by 159%.
SPUR claimed to model the 15 lowest-ridership BART stations, but substituted busier stations like Dublin/Pleasanton and Millbrae, inflating weekday boardings by 13.7% and generating 25% to 35% more diverted car trips.
For the 8,905 daily trips from 15 BART station closures to reach SPUR's 498-million vehicle-miles claim, each diverted driver would have to commute 224 miles round trip every working day.
Jacobs Engineering, which performed the traffic analysis for SPUR, holds ~$122 million in Bay Area transit contracts and contributed $150,000 directly to the pro-tax campaign committee.
The San Mateo County Transportation Authority alone held $973 million in cash and investments as of August 2026. SPUR never evaluated using existing agency reserves or interagency loans before raising sales taxes.
The 20-page technical paper dissects the methodology, data selections and political interests behind SPUR's claims. Here are the core findings documented in the report.
SPUR was not an independent, disinterested researcher evaluating public policy; it co-leads the Measure RTM political campaign. Report author Laura Tolkoff served as director and treasurer of the Connect Bay Area Transit Committee through April 2026. SPUR itself reported over $63,000 in in-kind campaign contributions.
Furthermore, technical consultant Jacobs contributed $150,000 directly to the campaign in three $50,000 installments in 2026. Jacobs holds approximately $122 million in authorized contracts and assigned work across BART, MTC, SFMTA, SamTrans, Golden Gate and Caltrain. Jacobs also recently entered into a $1 million settlement agreement with BART following an Inspector General investigation into Transbay Tube billing deficiencies. None of these financial relationships were disclosed in SPUR's report.
SPUR stated that its analysis assumed "the lowest-ridership BART and Caltrain stations" would close, claiming this choice made its findings "intrinsically conservative."
BART's October 2025 ridership records prove otherwise. SPUR omitted four genuine lowest-ridership stations: Milpitas (1,453 boardings), Lafayette (1,860), Berryessa/North San Jose (1,940) and North Berkeley (2,037). In their place, SPUR included high-ridership stations: Dublin/Pleasanton (3,434 boardings), Pittsburg/Bay Point (2,594), Millbrae (2,164) and Antioch (2,041). This cherry-picking inflated ridership by 13.7% and produced 25% to 35% more diverted automobile trips.
| Rank | Station | Weekday Boardings | Included in SPUR's 15? |
|---|---|---|---|
| 1 | Oakland International Airport | 558 | Yes |
| 2 | Pittsburg Center | 581 | Yes |
| 3 | North Concord/Martinez | 698 | Yes |
| 4 | Warm Springs/South Fremont | 1,356 | Yes |
| 5 | Castro Valley | 1,419 | Yes |
| 6 | West Dublin/Pleasanton | 1,432 | Yes |
| 7 | Milpitas | 1,453 | NO (Skipped) |
| 8 | Orinda | 1,478 | Yes |
| 9 | South San Francisco | 1,596 | Yes |
| 10 | South Hayward | 1,617 | Yes |
| 11 | San Bruno | 1,724 | Yes |
| 12 | Colma | 1,764 | Yes |
| 13 | Lafayette | 1,860 | NO (Skipped) |
| 14 | Berryessa/North San Jose | 1,940 | NO (Skipped) |
| 15 | North Berkeley | 2,037 | NO (Skipped) |
| True Lowest 15 Total | 21,513 | — | |
| SPUR Selected 15 Total | 24,456 | +13.7% Higher | |
The report claims that 56% of riders at an end-of-line closed station shift to driving, 30% shift at other closed stations and 25% shift at stations with reduced frequency. These percentages drive every downstream number in SPUR's congestion model, yet the report provides zero empirical data, calibration or sensitivity analysis to justify them.
SPUR claims service reductions would add 498 million vehicle-miles traveled (VMT) per year. But the 15 BART station closures generate only ~8,905 daily car trips, totaling about 33 million to 44 million VMT annually. Even accepting the 498-million figure at face value, total driving in the Measure RTM counties exceeds 135 million miles per day. SPUR's claimed traffic increase represents less than 1.4% of regional driving, an amount that is easily offset by modest increases in remote work.
SPUR's headline claim that morning Bay Bridge delays would increase by 33 minutes and evening delays by 43 minutes depends on unpublished hourly origin-destination matrices from Jacobs' subsidiary, StreetLight Data. Order-of-magnitude tests demonstrate that the result is borderline-plausible only under extreme assumptions and cannot be confirmed from public data.
SPUR modeled the transit crisis as a binary choice: pass a $1.37 billion per year sales tax or face catastrophic highway gridlock. The report never analyzed obvious alternatives:
Get the complete methodology breakdown, station-by-station reconstruction tables, sensitivity analyses and extensive primary source citations.
Download Full Report 20-Page PDF • 852 KBThe pro-tax campaign is backed by transit contractors and special interests. Our opposition effort is powered by grassroots contributions to inform voters across Alameda, Contra Costa, San Francisco, San Mateo and Santa Clara counties.