342
KSI Total
2015–2025 excl. 2020
53
Fatalities
City streets
1001
Visible Injuries
City streets
4,150
Total Collisions
City streets only
8.2%
Overall KSI Rate
342 / 4,150
19.2%
Alcohol KSI Rate
vs 6.8% non-alcohol
Annual collision trend by severity
2015–2025 excl. 2020 — gap in x-axis 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
Lighting conditions
At time of collision
Weather conditions
At time of collision
Motor vehicle involved with
What did the at-fault vehicle collide with?
Pedestrian movement at collision
Pedestrian-involved collisions only
High Injury Network Explorer
KSI Only: corridors with >2 KSI in 2021–25 (emerging-inclusive) · KSI+Vis: corridors with ≥5 visible injuries in 2021–25 · Click any row to expand
Metric:
Fatal present
KSI rate ≥10%
Standard HIN
Period Comparison
2015–2019 (5 yrs, pre-COVID) vs 2021–2025 (5 yrs, post-COVID) Equal 5-year windows · 2020 excluded · All metrics normalized per year or as ratesKSI rate per year — severity trending up or down?
Blue dots=2015–19 · Orange dots=2021–25 · The gap shows the era shift
Collisions per year by era
Volume trend (2020 excluded)
Collision type — KSI rate shift between eras
Blue=2015–19 · Orange=2021–25 · Higher = more deadly per incident
Primary collision factor — volume per year
Is the mix of causes changing?
HIN Corridor Rank Changes: 2015–2019 vs 2021–2025
Equal 5-yr periods · KSI/yr normalized. EMERGING entered HIN post-2020. COOLING left HIN. WORSENING KSI/yr ↑ >0.2. IMPROVING KSI/yr ↓ >0.2.
HIN Intersections: 2015–2019 vs 2021–2025
The Safety Story: 2015–2019 vs 2021–2025
Equal 5-year periods · 2020 excluded · All stats normalized for fair comparisonFewer Crashes, Far More Deadly
+21.8% KSI rate
KSI rate rose from 7.49% (2015–19) to 9.12% (2021–25) — a 21.8% increase in lethality per collision. Volume dropped ~9%/yr, but each crash is 22% more likely to kill or seriously injure. Concord faces a severity crisis, not a volume crisis.
Speed Crashes: 116% More Lethal
2.4% → 5.2%
Speed-related KSI rate more than doubled — from 2.4% to 5.2% (117% increase). Volume dropped slightly but each speed crash is dramatically more deadly. Post-pandemic higher operating speeds are the likely driver.
Concord Ave: Most Alarming Emergence
Not ranked → #3
Concord Ave was not in the top-20 in 2015–2019 (KSI rate: 1.8%). By 2021–2025 it reached #3 citywide at a 14.5% KSI rate. This street needs immediate intervention — it wasn't on the radar five years ago.
HIN Fragmentation: Danger Is Spreading
22 new streets
The HIN gained 22 new streets in 2021–25 not present in 2015–19, while 15 cooled down. Only 12 corridors persist across both periods — danger is spreading citywide making targeted investment harder.
Alcohol: Real Progress, Still Critical
22.6% → 16.0%
Alcohol KSI rate fell from 22.6% to 16.0%. DUI volume held steady at ~30/yr. A genuine win — but at 16.0%, alcohol crashes remain 2.4× more deadly than non-alcohol. Progress is real but the work isn't done.
Head-On: The One Clear Win
-31% vol + KSI rate ↓
Head-on volume dropped 31% AND KSI rate fell from 15.0% to 9.7% — the only type improving on both dimensions. Understanding what drove this could inform broader strategy.
Hit Object: Silent Escalation
+63% volume surge
Hit Object collisions surged 63% in volume (24→37/yr) with a persistent 13.9% KSI rate. More frequent AND consistently deadly — the fastest-deteriorating collision category. Fixed-object hazard audits on high-KSI corridors are warranted.
Intersection Hotspots Shifted Completely
Only 4 persist
Only 4 intersection hotspots appear in both 2015–19 and 2021–25. The near-complete turnover reinforces fragmentation — Concord's danger pattern has fundamentally changed post-COVID and requires a citywide re-assessment of intersection treatments.
Clayton Rd & Willow Pass: Still #1 & #2
Ranks held
Despite all the change, Clayton Rd and Willow Pass Rd have held the top two spots. Willow Pass rate actually worsened (7.8%→9.4%). These are Concord's chronic danger corridors — they need sustained multi-year investment rather than one-time fixes.
9.12%
2021–2025 KSI Rate
7.49%
2015–2019 KSI Rate
The headline: Concord's streets are getting more dangerous per collision, not less — and the pattern is spreading.
Comparing equal 5-year pre- and post-COVID windows (2020 excluded from both), every severity metric worsened except fatality rate and alcohol KSI rate. Speed, hit-object crashes, and a fragmented HIN with 22 newly-dangerous streets are the dominant drivers. Without targeted intervention — especially on emerging corridors like Concord Ave — this trajectory will continue.
AI-Powered Safety Insights
Multivariate patterns · 2015–2025 (excl. 2020) · Hard-to-discern findings ranked by policy impact
Alcohol Multiplier Effect
2.8×
Alcohol-involved KSI rate: 19.2% vs 6.8% non-alcohol. ~8% of collisions but 21% of all KSI.
DUI EnforcementDarkness Amplifies Severity
56%
Of pedestrian KSI occur in dark conditions. After-dark ped collisions are 3× more likely fatal or severe than daytime.
Street LightingCrosswalk False Security
40.6%
KSI rate outside crosswalk. Peds in a crosswalk still face 18.5% KSI rate. Physical protection needed.
Ped InfrastructureLate Night KSI Spike
19.0%
KSI rate 0–5 AM is 3.5× higher than midday (5.0%). Only 5.5% of collisions but ~12% of KSI.
High-Severity WindowAlcohol + Dark: Compound Risk
21.8%
Alcohol AND dark: KSI rate hits 21.8% — 2.7× city average. 7.6% of collisions, disproportionate harm.
Compound RiskWeekend Night Danger Window
15.1%
Fri/Sat/Sun after 9 PM: 15.1% KSI rate. Targeted enforcement these 3 nights addresses disproportionate fatal collisions.
Enforcement TimingCollision type × severity heatmap
Darker red = higher KSI rate
KSI rate by time window
Late night is 3.5× more dangerous than midday
Annual KSI vs total collisions
Volume declining but KSI rate rising — the key trend
Top 5 corridor persistence
Dangerous year after year
Pedestrian KSI by lighting × movement
Daylight paradox: most incidents daytime but dark is far deadlier
Day of week — volume vs KSI divergence
Weekdays higher volume; weekends higher KSI rate
View:
Severity
Fatal
Severe Injury
Visible Injury
Complaint of Pain
Flags
Pedestrian
Bicycle
Motorcycle
Alcohol