Did Chicago's Red-Light Cameras Make Intersections Safer?
The city claimed a 47 per cent fall in dangerous crashes. The independent number was smaller, and partly cancelled by rear-end collisions.
By The Standard
In this articleObservation
The Standard take
The cameras produced a real but modest safety effect, not the one advertised. An independent analysis commissioned by the Chicago Tribune and carried out by the Texas A&M Transportation Institute found right-angle injury crashes down about 15 per cent at camera intersections, and rear-end injury crashes up about 22 per cent. Netted out, the programme''s total injury-crash benefit was small…
Evidence rating: Emerging. This rating holds unless A current analysis — post-2015, using a proper comparison group of similar non-camera intersections — showing a sustained net reduction in injury crashes across the programme rather than at selected sites.
Key Findings
Evidence: Emerging- Chicago built the largest red-light camera programme in the United States — roughly 300 cameras at the peak — and defended it with a safety number: a 47 per cent reduction in dangerous crashes at camera intersections.
- Did the cameras reduce injury crashes, and by how much once you account for the crashes they cause?
- The cameras produced a real but modest safety effect, not the one advertised.
Observation
Chicago built the largest red-light camera programme in the United States — roughly 300 cameras at the peak — and defended it with a safety number: a 47 per cent reduction in dangerous crashes at camera intersections.
That figure came from the city. When someone else ran the analysis, it got a lot smaller.
The Question
Did the cameras reduce injury crashes, and by how much once you account for the crashes they cause?
The Standard take
The cameras produced a real but modest safety effect, not the one advertised. An independent analysis commissioned by the Chicago Tribune and carried out by the Texas A&M Transportation Institute found right-angle injury crashes down about 15 per cent at camera intersections, and rear-end injury crashes up about 22 per cent. Netted out, the programme''s total injury-crash benefit was small and concentrated at a minority of sites.
Historical Context
The programme began in 2003 and expanded fast. Its public justification was always the T-bone crash: a vehicle entering on red struck side-on, the collision type that injures and kills out of proportion to its frequency. The trade-off inherent in the technology was known from the start — drivers who brake hard to avoid a ticket get hit from behind — but the city''s own reporting never carried it.
What the Evidence Shows
The 2014 Texas A&M analysis is the closest thing to an arms-length verdict on the Chicago programme specifically. Three findings stand out.
Right-angle injury crashes fell, by roughly 15 per cent. That is the effect the programme exists to produce, and it is genuinely there.
Rear-end injury crashes rose, by roughly 22 per cent. Rear-end collisions are on average less severe, which is why a net benefit can survive that increase — but it is a real cost paid by real people, and it belongs in the accounting.
The city''s 47 per cent claim did not survive contact with a proper comparison. The gap came largely from methodology: comparing camera intersections to their own prior record, at sites selected because they had unusually bad recent years, without controlling for the tendency of extreme values to drift back toward normal.
The other well-documented issue was enforcement integrity rather than safety: yellow-light intervals sitting at the 3.0-second threshold, and disputed ticket spikes, both examined by the city''s Inspector General. A programme whose revenue depends on a timing parameter has an obvious incentive problem, and that is separate from whether the cameras work.
The Counterargument
The broader literature is kinder to red-light cameras than Chicago''s implementation is. Multiple multi-city studies find reductions in fatal red-light-running crashes where programmes are well sited and yellow timing is set properly. The finding here is not "cameras do not work." It is "this programme, at these intersections, delivered a fraction of what was claimed."
Conclusions
Lengthening yellow intervals and re-siting cameras to the intersections with genuine angle-crash histories would likely produce more safety per camera than the programme did at its largest. The most defensible version of this policy is smaller than the one Chicago built.
What would change our mind
A current analysis — post-2015, using a proper comparison group of similar non-camera intersections — showing a sustained net reduction in injury crashes across the programme rather than at selected sites. Site-level data on yellow-interval changes and crash outcomes would settle the incentive question at the same time.
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Last Updated
September 17, 2026
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· Editorial verdictBased on the evidence presented,
Second City Standard believes The city claimed a 47 per cent fall in dangerous crashes. The independent number was smaller, and partly cancelled by rear-end collisions.
Remaining uncertainty: Awaiting a final written verdict from the editorial desk.
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