123
KSI Total
2015–2025 excl. 2020
10
Fatalities
People killed
757
Visible Injuries
City streets
1,305
Total Collisions
City streets only
9.4%
KSI Rate
123 / 1,305
22.6%
Alcohol KSI Rate
vs 7.9% non-alcohol
Annual collision trend by severity
2015–2025 excl. 2020 — gap marks excluded year
Severity breakdown
All city street collisions
Collision type distribution
Count by type
Primary collision factor
Top contributing factors
Collisions by hour of day
Red=late night · Yellow=PM peak
Day of week
Volume by weekday
What vehicle hit
Motor vehicle involved with
High Injury Network Explorer
Sorted by KSI · All years 2015–2025 excl. 2020 · City streets only
Era Comparison
2015–2019 (pre-COVID) vs 2021–2025 (post-COVID) Equal 5-year windows · 2020 excluded · All metrics normalizedKSI rate per year — trend
Blue=2015–19 · Orange=2021–25
Volume per year
Crash count trend by era
Collision type — KSI rate shift
Blue=era A · Orange=era B · Higher = more deadly per crash
Primary factor — volume/year
Is the mix of causes changing?
HIN Corridor Changes: 2015–19 vs 2021–25
The Safety Story: 2015–2019 vs 2021–2025
Equal 5-year periods · 2020 excluded · Stats normalized for fair comparisonCatastrophic Post-COVID KSI Surge
+73.3%
KSI rate surged from 6.93% to 12.01% — a 73.3% increase. One of the highest post-COVID surges in Contra Costa County. Urgent systemic intervention required.
Speed: #1 Cause of Crashes & KSI
6.4% → 8.4%
Unsafe Speed is the #1 PCF in Brentwood with 409 crashes. Speed KSI rate: 6.4% (era A) → 8.4% (era B). Physical calming, feedback signs, and road diet evaluation are the priority responses.
BRENTWOOD BL: Worsening
7 → 14 KSI
BRENTWOOD BL is the #1 HIN corridor with 21 total KSI (2 fatal). KSI worsening era A→B — immediate capital intervention warranted.
HIN: Danger Spreading
11 new corridors
11 new corridors emerged in 2021–25 not present in 2015–19. 9 corridors persist across both eras. Systemic citywide programs needed alongside targeted corridors.
Alcohol: Persistent Risk
21.4% → 23.8%
Alcohol KSI rate rose from 21.4% to 23.8%. At 23.8%, alcohol crashes remain 2.9× more deadly than non-alcohol. DUI enforcement must intensify.
Motorcycle Fatality Risk
26.5% → 37.8%
Motorcycle KSI rate: 26.5% → 37.8%. 71 crashes, 23 KSI. Late-night weekend concentration amplifies severity — enforcement targeting these windows is essential.
Dark KSI Improving
13.9% → 13.0%
Dark-condition KSI rate improved: 13.9% → 13.0%. 349 dark crashes, 47 KSI. Lighting improvements are working — maintain investment.
Volume vs Severity
133/yr → 128/yr
Crash volume: 133/yr (era A) → 128/yr (era B). Volume fell but KSI rate surged — severity crisis, not a volume crisis.
Top Intersection: OHARA AV & LONE TREE WY
2 KSI
OHARA AV & LONE TREE WY — 2 KSI (0 fatal), 7 crashes. Era A: 0 KSI → Era B: 2 KSI. Targeted intersection capital recommended.
AI-Powered Safety Insights
Multivariate patterns · Brentwood city streets 2015–2025 (excl. 2020) · Ranked by policy impact
Alcohol Multiplier Effect
2.9×
Alcohol KSI rate: 22.6% vs 7.9% non-alcohol. 10.2% of crashes, 24.4% of KSI.
DUI EnforcementDark Condition KSI Rate
13.0%
KSI rate in dark: 13.0% era B — 1.4× city average. 349 dark crashes, 47 KSI. LED intersection lighting addresses this directly.
Street LightingPedestrian KSI Rate Elevated
14.6%
Pedestrian KSI rate: 14.6% across 96 crashes (14 KSI). 24.0% of ped crashes in dark — LED lighting and RRFB crossings are the priority response.
Ped InfrastructureLate Night KSI Spike
12.8%
KSI rate 0–5 AM is 2.3× higher than midday (5.6%). 0.0% of crashes, concentrated fatal risk window.
High-Severity WindowAlcohol + Dark: Compound Risk
21.7%
Alcohol AND dark: KSI rate hits 21.7% — well above city average of 9.4%. Disproportionate harm from this combination.
Compound RiskMotorcycle Danger Window
32.4%
Motorcycle KSI rate: 32.4% — 3.4× city average. 71 crashes, 23 KSI. Late-night weekend is highest-risk window.
Motorcycle SafetyCollision type × severity heatmap
Darker = higher KSI rate
KSI rate by time of day
When is each crash most likely to be fatal or severe?
Annual KSI vs total collisions
Volume declining but severity rising — the key trend
Top 5 corridors — KSI persistence
Dangerous year after year
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Showing
—
KSI
—
Fatal
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KSI Rate
Severity
Fatal
Severe
Visible
Pain
SS4A FY2026 Implementation Grant — Project Portfolio
Three plans based on 2021–2025 post-COVID crash data · May 26, 2026 deadline
HSIP Cycle 13 — Project Recommendations
Cross-cycle C8–C12 analysis · Brentwood award history · 2021–2025 crash data
$5M–$18M est. portfolio
HSIP Grant Intelligence Module
Synthesized from Cross-Cycle Analysis C8–C12 · Countermeasure Trends · C12 Report & Funded Projects List
$1.10M
Brentwood HSIP Won
C12
1
Projects Funded
Prior award cycles
$1.15B
Program Total
1,281 projects C8–C12
$5–18M
C13 Portfolio Target
6 recommendations
Brentwood HSIP Application History
C13 Statewide Intelligence
🚀 Rising Countermeasures (C8→C12)
Gaining frequency & funding — prioritize for C13
LPI: 0→33 projects · +33
RRFB/Beacons: 11→57 · +46
Retroreflective Backplates: 1→23 · +22
Class IV Bike Lanes: 14→31 · +17
Raised Medians: 8→19 · +11
📉 Declining Countermeasures
Losing funding share — supplement but don't lead with these
Signal Timing Only: 45→12 · -33
Striping/Delineation Only: 28→9 · -19
Guardrail: 22→8 · -14
Rumble Strips Only: 11→4 · -7
BCR Sweet Spot
$1.5M–$4M
Brentwood should target $1.5–3.5M per BCR application. Stack 3+ countermeasures for highest BCR score.
Best Win Strategy
3-CM Stack
C12 winners averaged 3+ countermeasures per application. Prior C12 wins provide competitive positioning.
VRU Pool
201 VRU
96 ped + 105 bike = 27 KSI. Qualifies for VRU Special Rule set-aside.