Lại chả đúng

-----

Electronic signs (biển báo điện tử) are a common (phổ biến) sight on US highways (đường cao tốc). These dot-matrix displays (bảng điện tử) date back to at least the 1950s and were first used to alert drivers to changing speed limits (hạn chế tốc độ) or hazards ahead (nguy hiểm phía trước); they now usually exhort us to drive safely.

But targeting drivers with safety messages when they're driving may actually be counterproductive (phản tác dụng), according to a study published this week in Science. In fact, giving drivers an update on the current year's road death total actually led to an increase in crashes (vụ đâm xe).

Jonathan Hall and Joshua Madsen used Texas to study the impact of safety messages on highway safety, thanks to a unique feature of the state—it only displays the state-wide road death count (đếm tỷ lệ tử vong trên đường) on electronic highway signs in the week leading up to each month's Department of Transportation meeting. That allowed the researchers to compare crashes downstream of an electronic sign during those weeks with the rest of the month, and to look back to crashes on the same stretch of road during the years before the safety campaign started in 2012.

The results are not encouraging. Crashes increased downstream of electronic signs during the weeks that the signs displayed updates on traffic deaths in Texas. And like chained-together combos in a macabre video game, the increased rate of crashes per hour remained elevated along stretches that had multiple electronic signs; otherwise, the effect diminished to background 4-6 miles (6-10 km) downstream of an electronic sign.

The overall increase in crashes was not large, but it was statistically significant: 2.7 percent over the first 0.6 miles (1 km), dropping to 1.8 percent at 4-6 miles downstream of a sign.

Bài trước: Vậy thua là đúng