Car crashes: Traffic accident statistics on signs may do more harm than good

The variety of crashes on Texan roads elevated when digital indicators had been used to show driving fatality figures

By Matthew Sparkes

Digital indicators above US highways that spotlight annual visitors fatalities are meant to shock individuals into driving safely, however statisticians warn there’s compelling proof they really trigger accidents.

Though the messages are displayed in lots of US states, Jonathan Corridor on the College of Toronto in Canada and his colleagues selected to look at crash knowledge from Texas as a result of the state makes use of digital indicators for fatality warnings only one week out of every month, offering ample management knowledge for comparability.

The researchers in contrast the variety of crashes from the 2 years earlier than the indicators had been launched with 5 years of knowledge whereas they had been in place. They found that displaying a fatality message elevated the variety of crashes on the ten kilometres of street after the signal by 4.5 per cent. Their findings counsel fatality messages induced a further 2600 crashes and 16 deaths per 12 months throughout Texas.

Corridor places the impact right down to distraction and the rise in a driver’s cognitive load whereas absorbing the knowledge. “You see it and also you’re fascinated about it, and so that you don’t put in your brakes fairly as quickly, and these little errors, 1 in 50 occasions, would possibly trigger a crash,” he speculates. “The proper proof could be a randomised management trial. I wish to be clear that we don’t have that. However I feel we even have actually, actually compelling proof.”

He says that the variety of fatalities displayed on an indication additionally adjustments its impression as bigger numbers are extra surprising. In Texas, the state fatality numbers had been reset every year in February and the crew noticed a giant drop in crashes in February in contrast with January.

Corridor says his crew has written to all states that present such warning messages and requested them to collaborate on additional analysis, however they’ve obtained little constructive response. “For those who’re going to do a security marketing campaign, it’s not that tough to say, ‘hey, let’s randomly draw 5 weeks from the following six months to point out this signal, and analyse crashes’. However they haven’t executed that, as a result of there’s only a presumption that the indicators can’t harm,” he says.

The Texas Division of Transportation didn’t reply to a request for remark, however is known to now not show such warning messages above highways.

Journal reference: Science, DOI: 10.1126/science.abm3427