GiveBetter x SF

Walk San Francisco

Conditional health value of a $100,000 unrestricted gift across implementation advocacy, education and survivor support

Research time: ~6 min on GPT-6 Astra Lite + GPT-5.6 Sol
  • Research — reviewed programs, finances and impact evidence.

Published: September 8, 2026.

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Summary

What do they do? Walk SF works on street-safety implementation, organizing, education, policy and support for survivors and families. The 2026 Slow Our Streets campaign is real; the modeled bundled engineering package is hypothetical. We evaluate non-electoral implementation and accountability, not candidate or party persuasion. More

Why this approach interests us

  • Physical traffic-calming has controlled injury evidence. Accelerating a substantial package could prevent deaths and severe injuries before the no-gift baseline catches up.

Our main reservations

  • Neither the next gift’s causal contribution nor the otherwise-delayed street package is verified. Utility and residence shares are judgments; the primary death-effect interval includes no effect.

What do you get for your dollar?

Our conditional central estimate is $5.80 million per 10 SF-resident QALYs, or $4.58 million per 10 Bay-resident QALYs including SF. A demanding favorable joint scenario reaches $31,700/$28,300 in donor cost, but not under the same public-resource boundary. These are analyst judgments about prospective implementation, not observed organizational effects or a priced donation offer. Inspect the complete model and sources.

central donor cost / 10 qalys
$5.80M SF / $4.58M Bay — Same $100,000 gift yields .172449 SF QALY and .218435 Bay QALY. Bay includes SF; do not add them.
whole-gift boundary
$100,000 once — $60,000 implementation; $15,000 other policy/education; $15,000 survivor support; $10,000 other/shared reserve. Allocation is judgmental; all cost retained.
recipient
Walk San Francisco Foundation — EIN 47-2000881, supported by official historical IRS letter and provider-posted FY2024–25 Form 990; not current tax advice.
financial scale
$981,449 FY2024–25 expenses — A filed Form 990, not audited statements or a unit-cost quote. A $100,000 gift is material, about 10% of that expense base.

1. What do they do?

Walk SF works on street-safety implementation, organizing, education, policy and support for survivors and families. The 2026 Slow Our Streets campaign is real; the modeled bundled engineering package is hypothetical. We evaluate non-electoral implementation and accountability, not candidate or party persuasion.

Fund the portfolio

Required implementation staff, administration and fundraising fit inside its $60,000 share; other allocations are not a second overhead charge.

Advance an otherwise-delayed package

The central 10% joint probability includes coalition attribution, fundraising replacement, public approval, failure and projects happening anyway. Do not multiply another allocation or additionality discount.

Prevent injuries during acceleration

Central success covers 2% of baseline fatal/severe risk for two years. These are risk-weighted exposures, not shares of residents or street length.

Follow finite health consequences

Only injuries prevented before the comparator catches up count. Their finite subsequent health consequences can extend beyond the acceleration period.

Scope of this review. Existing cameras, daylighting and scheduled public projects are baseline. No historical citywide decline, all endorsed projects or full legislative victory is attributed to the gift. Other portfolio benefits remain unquantified, not established absent.

2. Monitoring and information sharing

London physical 20-mph zones, 1986–2006

Controlled interrupted time series; Grundy et al., BMJ 2009. All-casualty reduction 41.9%; killed/seriously injured 46.3%; deaths 35.1% with interval −1.9% to 72.0%. Recent-period estimates were smaller.

Our assessment. No QALYs measured; physical engineering differs from signs, cameras, advocacy and some SF arterial conditions. Fatal and nonfatal outcomes remain separate.

SF city traffic events, including nonresidents

Official surveillance descriptions. 25 deaths in 2025; a separate historical average near 550 severe injuries annually.

Our assessment. Combining different periods is a planning assumption, not a current matched-year injury dataset.

Walk SF’s current work and FY2024–25 finances

Official organization portfolio and filing. Real implementation work and a roughly $1M expense scale; no verified gift-to-street effect.

Our assessment. Historical contributions and expense proportions do not establish marginal impact or funding room.

3. Qualitative assessment

Physical traffic-calming has controlled injury evidence. Accelerating a substantial package could prevent deaths and severe injuries before the no-gift baseline catches up.

Key reservations

  • A small unrestricted gift may replace existing support or fail to alter public implementation.
  • SF target roads may not match London physical-zone evidence; deaths are statistically uncertain.
  • Finite utility, competing mortality, severity mix, target risk share and residence shares are judgments.
  • The favorable multi-corridor package is not demonstrated current capacity or a grant offer.
  • A publicly funded study is not an unfunded construction need. The District 2 web timeline is internally inconsistent; do not infer completed 2027 construction.
  • Funding deficit, annual expenditure and general donation options do not establish room for more effective funding.

Benefits not included in our estimate

  • Survivor and family health effects
  • Education and civic welfare
  • Walking, pollution or fear-of-traffic benefits
  • Caregiver benefits and medical savings
  • Any electoral persuasion or duplicate advocacy credit

4. What do you get for your dollar?

$5.8M per 10 SF QALYs; $4.58M per 10 Bay QALYs

Central/favorable projects open at the beginning of year 2; pessimistic at year 3. Count event years 2–3, 2–6 or year 3 respectively, placing events at year-end. Fatal and nonfatal health trajectories are then discounted from those events; the two timing discounts cover different periods. Geography is an unmeasured residence prior: central 75% SF, 20% other Bay, 5% outside Bay; favorable 85/10/5%; pessimistic 60/25/15%. City location is not resident identity.

A better life is our comparison unit of 10 additional quality-adjusted life years (QALYs), potentially spread across people. These are uncertain estimates, not measured returns or verified donation offers.

How we calculate the estimate

Incremental health: Q = attribution probability × risk share × discounted acceleration years × (fatal incidence × fatal reduction × finite fatal Q + nonfatal severe incidence × severe reduction × finite injury Q), partitioned by residence minus independent donor-specific harm.
Central: .172449 SF QALY / .218435 Bay QALY for the same $100,000.

Model inputs and assumptions
Joint chance of additional acceleration
10% (range: 1%–35%; zero tested). Conditional on $60,000 implementation allocation, includes failure and replacement. Analyst judgment.
Annual baseline fatal / nonfatal severe injuries
25 / 550 (range: 15 / 300 pessimistically). 25 deaths in 2025 is official; 550 is historical annual severe-injury average, not a 2025 count. Mixed source periods.
Risk-weighted package reach / acceleration
2% / 2 years (range: 0.5% / 1 year to 8% / 5 years). Not a verified project or inexpensive access to high-injury streets. Analyst judgment.
Fatal / severe risk reduction
10% / 20% (range: 2% / 5% to 35% / 40%; null and harm tested). Physical-zone evidence, not cameras or signs alone; death-only primary interval crosses zero. Transferred judgment.
Finite QALYs per fatal / severe event prevented
12.31 / .283 (range: 5.61 / .029 to 16.82 / .687). Fatal utility .80/.85/.65, annual hazard .02/.01/.05 and 30/40/15 years; severe loss .10/.15/.03 for 3/5/1 years; 3% discount. Analyst judgment.

Same $100,000 gift under different assumptions

  • central: $5.8M SF / $4.58M Bay per 10 QALYs. 0.17245 SF QALYs and 0.21844 Bay QALYs including SF. Matched-build timing cost: $6.34M per 10 SF QALYs; gross forward-resource stress: $11.64M. Joint assumptions, not confidence limits.
  • favorableJointStress: $31.68K SF / $28.34K Bay per 10 QALYs. 31.567 SF QALYs and 35.281 Bay QALYs including SF. Matched-build timing cost: $105.63K per 10 SF QALYs; gross forward-resource stress: $384.19K. Joint assumptions, not confidence limits.
  • pessimisticPositive: $17.19B SF / $12.13B Bay per 10 QALYs. 0.000058183 SF QALYs and 0.000082426 Bay QALYs including SF. Matched-build timing cost: $17.22B per 10 SF QALYs; gross forward-resource stress: $17.69B. Joint assumptions, not confidence limits.
  • nullAdditionality: No positive-health ratio SF / No positive-health ratio Bay per 10 QALYs. 0.0000 SF QALYs and 0.0000 Bay QALYs including SF. Matched-build timing cost: No positive-health ratio per 10 SF QALYs; gross forward-resource stress: No positive-health ratio. Joint assumptions, not confidence limits.
  • nullInjuryEffect: No positive-health ratio SF / No positive-health ratio Bay per 10 QALYs. 0.0000 SF QALYs and 0.0000 Bay QALYs including SF. Matched-build timing cost: No positive-health ratio per 10 SF QALYs; gross forward-resource stress: No positive-health ratio. Joint assumptions, not confidence limits.
  • fatalEffectNull: $11.53M SF / $9.11M Bay per 10 QALYs. 0.086704 SF QALYs and 0.10983 Bay QALYs including SF. Matched-build timing cost: $12.6M per 10 SF QALYs; gross forward-resource stress: $23.16M. Joint assumptions, not confidence limits.
  • harmfulRiskTransfer: No positive-health ratio SF / No positive-health ratio Bay per 10 QALYs. -0.025819 SF QALYs and -0.032704 Bay QALYs including SF. Matched-build timing cost: No positive-health ratio per 10 SF QALYs; gross forward-resource stress: No positive-health ratio. Joint assumptions, not confidence limits.
  • nullAdditionalityDonorHarm: No positive-health ratio SF / No positive-health ratio Bay per 10 QALYs. -0.010000 SF QALYs and -0.020000 Bay QALYs including SF. Matched-build timing cost: No positive-health ratio per 10 SF QALYs; gross forward-resource stress: No positive-health ratio. Joint assumptions, not confidence limits.

Uncertainty. With other central assumptions unchanged, even 100% attribution produces only about 1.72 SF QALYs, short of the >10 needed for <$100,000 per 10 QALYs. Favorable upside requires jointly different reach, effect or duration—not merely proving some donor contribution.

5. Funding and previous grants

No identified marginal package, counterfactual completion date, complete public-capital budget or verified unused organizational capacity.

Donor numerator is the full gift. The separate matched-build perspective adds expected early-versus-later capital PV and extra maintenance: total $109,289/$333,432/$100,174 centrally/favorably/pessimistically. Gross forward spending without later-build credit is $200,803/$1,212,790/$102,919. Capital allowances $1M/$3M/$300K and maintenance $20K/$60K/$10K are unquoted judgments. These comparisons omit some displaced projects, volunteer time, disruption and medical offsets; neither is a fully priced social CEA. Deduplicate any shared public package and health attribution with SPUR and other advocates.

This review does not establish a verified marginal funding offer or a complete history of grants.

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Opens the organization’s giving page. A general donation may not fund the specific activity modeled here; confirm allocation with the recipient.

6. Sources

  1. Slow Our Streets, 2026 campaign. Walk San Francisco. Official campaign page. Published: Undated current 2026 page; retrieved: September 8, 2026.
  2. 2025 Impact Report. Walk San Francisco. Organization-authored impact report. Published: 2025 report; postedJune 2026; retrieved: September 8, 2026.
  3. FY2024–25 Form990. Walk San Francisco Foundation. Provider-posted Form 990 filing. Published: July 1, 2024–June 30, 2025; preparerMay 14, 2026; retrieved: September 8, 2026.
  4. Determination letter. IRS, hosted by organization. Historical IRS determination letter. Published: February 26, 2015; exemptioneffectiveSeptember 14, 2014; retrieved: September 8, 2026.
  5. Traffic Fatalities Drop by Nearly Half in2025. SFMTA. Official surveillance press release. Published: January 8, 2026; retrieved: September 8, 2026.
  6. Community Health Assessment2024. SFDPH. Official community health assessment. Published: 2024; cleanedApril 2025; retrieved: September 8, 2026.
  7. Effect of20mphtraffic speedzones on roadinjuries. Grundy et al., BMJ / LSHTM. Primary controlled interrupted time-series study. Published: December 10, 2009; retrieved: September 8, 2026.
  8. District2 Safety Study. SFMTA. Official publicly funded project page. Published: Undated currentpage; checkedSeptember 8, 2026; retrieved: September 8, 2026.
  9. New High Injury Network map. SFMTA. Official risk-network description. Published: 2026 currentpage; retrieved: September 8, 2026.
  10. Laurel Heights/Jordan Park historicaltrafficcalming plan. SFMTA. Historical engineering cost document. Published: FY 2012–17schedule, not 2026price; retrieved: September 8, 2026.

Annual expenses: years and sources

Average annual expenses (three consecutive fiscal years): $921,898. Organization size is separate from the modeled cost-effectiveness of a donation.

Walk San Francisco Foundation

Whole-organization Form 990 Part I line 18; fiscal year ending June 30, labeled by ending year.

2025 is July 1, 2024–June 30, 2025, despite the return's 2024 tax-form label. Official provider-posted return page 1 verifies EIN, period, and current/prior expense. The 2024 return supplies 2023 comparative.