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jon ben-menachem
@jbenmenachem.com

Our new study provides rare causal evidence about NYC’s speed camera program. We find large reductions in collisions (30%) and injuries (16%) near intersections with cameras. www.pnas.org/doi/abs/10.1... @astagoff.bsky.social ky.social @brendenbeck.bsky.social nbeck.bsky.social 🧪

pnas.orgCan speed cameras make streets safer? Quasi-experimental evidence from New York City | PNASEach year, approximately 40,000 people die in vehicle collisions in the United States, generating $340 billion in economic costs. To make roads saf...

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jon ben-menachem
@jbenmenachem.com

NYC’s speed cameras are remarkably lenient: violations carry a flat $50 fine with no points (compared to hundreds of dollars and 3-11 points for police-issued tickets). They are also limited to school zones. Even so, we observe large safety benefits. 🧪 www.pnas.org/doi/abs/10.1...

pnas.orgCan speed cameras make streets safer? Quasi-experimental evidence from New York City | PNASEach year, approximately 40,000 people die in vehicle collisions in the United States, generating $340 billion in economic costs. To make roads saf...
jon ben-menachem
@jbenmenachem.com

When cameras are installed, they issue many violations in the first month, followed by a steep decline in the second month. This suggests that the cameras effectively deter speeding by changing underlying driver behavior rather than relying on sustained revenue extraction.

jon ben-menachem
@jbenmenachem.com

Although many studies evaluate traffic cameras, very few apply causal inference methods. Some scholars who implement stronger designs argue that they eliminate the observed safety benefits of cameras. Yet we find substantial effects using the Callaway and Sant’Anna diff-in-diff estimator.

jon ben-menachem
@jbenmenachem.com

Automated enforcement provides important benefits. Cameras swiftly impose certain sanctions for reckless driving without the risk of human bias (i.e., racial discrimination). And unlike police traffic stops, speed cameras do not carry the risk of escalation into arrest or violence.

Nathan Tankus
@nathantankus.bsky.social

Looks really great! One question since I'm unfamiliar with the literature here- is there lots of evidence that points on a license are effective deterrents? If so do you have any intuition of just how large the "points on the license" effect would be?

jon ben-menachem
@jbenmenachem.com

I haven't done a review of lit on points but my sense is that it matters. Issues in comparing -- geo context diffs, huge modeling differences btwn soc sci causal inference and traffic engineering/safety lits. (1) www.sciencedirect.com/science/arti... (2) www.sciencedirect.com/science/arti...

sciencedirect.comSelf-reported deterrence effects of the Norwegian driver’s licence penalty point systemNorway’s penalty point system implies that traffic infractions are penalised with two or three points for full-licence drivers and four or six points …
Nathan Tankus
@nathantankus.bsky.social

Yeah this is the biggest thing I was wondering- does points on the license matter for *deterrence* or enforcement against people who will drive dangerously up to the point that they lose their license.

tagerai.bsky.social
@tagerai.bsky.social

Nice! I love additional results on freq, race, spillovers etc. A couple more Qs- my sense is some people dislike speed cameras- do you think that's b/c they issue more tickets? B/c they're more fair? Can you look at effects on any other crime? Does it save money? What do cops do w/their new time?

jon ben-menachem
@jbenmenachem.com

On perceptions... also speculation... I imagine people don't like getting tickets / being forced to drive the speed limit (human traffic enforcement, afaik, has more of a 'window of acceptable speeding' than cameras). There's also legit surveillance concerns

Aaron Stagoff
@astagoff.bsky.social

FWIW TA found that the program enjoys majority support in NYC, which rose over time. Other polling has show that support increases when people are prompted with safety messaging. transalt.org/press-releas...

transalt.orgNew Poll Reveals New York City Voters Support Automated Enforcement to Make Streets Safer — Transportation AlternativesClear Majority of New York City Voters Support Adding More Speed Safety Cameras, Expanding Program Beyond School Zones, Using Automated Enforcement To Curb Reckless Driving   By a 23 point...