10/15/2026
“Off the Rails” cites unjustified assumptions, unpublished data, undisclosed financial ties, no analysis of alternatives, and calls for transparent data and a full comparison of alternatives before voters are asked to approve billions in new taxes.
BAY AREA, Calif. - The Committee for Affordable Bay Area Transit today released Off the Rails, a 20-page technical assessment of Bumper to Bumper, the September 2026 SPUR report that projects severe Bay Bridge delays and added driving, if voters reject Measure RTM and San Francisco’s Proposition H. The two tax measures would raise roughly $1.37 billion a year. The new technical assessment finds that SPUR’s dramatic traffic projections rest on unvalidated behavioral assumptions and unpublished inputs - and that its conclusion that Measure RTM and San Francisco’s Proposition H are the only realistic and timely solutions is not supported by the SPUR report.
The assessment, “Off The Rails: A Technical Assessment of SPUR’s Bumper to Bumper Report,” reconstructs and evaluates calculations using SPUR’s published appendix and BART’s October 2025 ridership and origin-destination data. It does not claim that service cuts would have no traffic impact. Rather, it finds that SPUR’s estimates should be treated as an unverified scenario, not a reliable forecast nor proof that new taxes are the only option.
Key findings
· Expert Review of SPUR Report Concludes: “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.”
- Professor Damian Park, Santa Clara University, Economics Dept
· SPUR’s conclusion is not supported by the analysis. SPUR does not test cost restructuring, fare changes, bus rapid transit, congestion pricing, employer or payroll funding, micro-transit, interagency use of existing cash, or how commuters and businesses would adapt.
· Financial ties were not disclosed. SPUR co-led the campaign supporting RTM, and the report’s author previously held campaign leadership and treasurer roles. Jacobs, the technical consultant, contributed $150,000 to the campaign and has approximately $122 million in authorized contracts and assigned work with regional transit agencies. These relationships create an appearance of bias and conflict of interest concerns.
· Critical assumptions are not validated. Among other unjustified inputs, assumed shifts from transit to driving - 56% at certain closed end-of-line stations, 30% at other closed stations, and 25% under frequency reductions - are not supported by disclosed calibration, data or sensitivity testing.
· Results cannot be independently reproduced. Among other omissions, the station-by-hour diversion matrix and the StreetLight traffic data underpinning the Bay Bridge traffic delay figures were not published.
· The “lowest-ridership stations” claim is inaccurate, and affects the results. SPUR claimed it modeled closing the 15 lowest ridership stations. However, the 15 stations SPUR selected recorded higher weekday boardings, worth roughly 25 - 35% more diverted trips.
· The financial analysis is incomplete. On a cash-flow basis, using the report’s own figures, the two taxes would cost residents about $1.2 billion per year more than not adopting them. The review notes this is not a net-welfare estimate, because the report does not value delays, emissions or lost service. SPUR provided no financial assessment of why cost per passenger-mile has risen about 159% since 2019, nor what the financial impacts of service cuts aside from SFMTA (Muni) would be on the operating deficits.
A major, regressive tax decision requires more than a worst-case scenario
“The central issue is not whether service cuts could affect traffic,” the assessment concludes. “It is whether the SPUR analysis supports the scale of the claims and proves that new taxes are the only realistic solution. It does not.”
The report calls for publication of the underlying data and calculations, independent review of the traffic analysis, and a comprehensive comparison of genuine alternatives - including operating-cost reforms and the use of existing agency financial resources - before voters are asked to approve additional large, long-term tax measures.
“Before asking residents to pay billions of dollars in extra taxes, decision-makers should demonstrate what the money will accomplish, examine why costs have risen, and compare the alternatives in services and technology.”
The Committee is also asking media to give this rebuttal the same coverage it gave the SPUR Bumper To Bumper report, and to retract any prior claims that the SPUR report was impartial or independent.
Read the report summary, and detail
“Off The Rails: A Technical Assessment of SPUR’s Bumper to Bumper Report” - [Download Full Report]