Safety evidence

What traffic cameras can prove, and what they cannot

Speed cameras can change behavior and may reduce serious crashes. Red light camera results are more mixed. Neither finding settles whether a vast, flat-fine revenue system is fair or democratically legitimate.

Evidence review updated July 23, 2026

The short answer

The strongest evidence supports targeted speed enforcement as one tool among many. The record does not justify treating every camera, every location, every fine structure and every revenue practice as equally effective.

This project does not claim that cameras never work. It challenges a common leap: because some automated enforcement can improve some safety outcomes, any scale of deployment and any financial design must be accepted without a vote.

Speed cameras

The evidence is favorable, but the effect is not a blank check.

What is supported

Systematic reviews and location studies commonly report less speeding and reductions in some injury crashes near speed-camera sites.

What varies

Effects differ by road type, baseline crash history, camera visibility, enforcement threshold, follow-up period and whether nearby crashes are displaced.

Regression to the mean

Cameras are often placed where recent crashes were unusually high. Some decline may occur even without intervention, so stronger studies use comparison locations and longer periods.

Location-level accountability

A city should publish before-and-after speeds, crashes and severity for every site instead of relying only on a citywide total.

Starting sources: Cochrane review; Federal Highway Administration.

Red light cameras

Crash type and severity matter.

Red light camera studies often report fewer right-angle crashes, which can be severe, alongside increases in rear-end crashes. A headline that says “crashes fell” or “crashes rose” can conceal that tradeoff. Signal timing, especially adequate yellow intervals, is a critical part of the analysis.

Starting source: Insurance Institute for Highway Safety overview.

The DC claim

A dramatic decline is not the same as a causal estimate.

DC traffic deaths declined from 52 in 2024 to 25 in 2025. That is good news. It is also a single annual comparison during a period with multiple policy, engineering and enforcement changes.

To attribute the decline to STEER or camera expansion, DC would need a design capable of separating camera effects from roadway changes, traffic exposure, police activity, vehicle technology, weather and normal year-to-year variation. The public should see location-level results and a transparent methodology.

Our test:

If a location is safer, publish the before-and-after speeds, crashes, severity and exposure. If the data are convincing, the program should withstand both scrutiny and a public vote.

The Washington Post reported both the 2025 decline and that deaths remained near the level recorded a decade earlier: March 2026 analysis.

FAQ

Questions people ask

Are cameras safer than police stops?

Automated enforcement can reduce discretionary roadside encounters, but the policy choice is not limited to cameras or police stops. Street design, signal timing, narrower lanes, raised crossings and other engineering approaches can reduce dangerous behavior without either.

Does questioning DC's statistics mean opposing safety?

No. Demanding a valid causal claim is part of taking safety seriously.

What does the Camera Tax Project support?

Engineering first, targeted and publicly approved enforcement, income-scaled fines, no poverty penalties, transparent site-level evaluation and safety-dedicated revenue.