Have smartphones, pot become deadly for pedestrians?

(HealthDay)—For the second year in a row, U.S. pedestrian deaths hit highs not seen in decades, new data shows.

Greater use of marijuana and smartphones may be the reason why, the research suggests.

The annual pedestrian death tolls in 2016 (5,987) and 2017 (5,984) should serve as a warning, said Jonathan Adkins, executive director of the Governors Highway Safety Association (GHSA), which compiled the report.

"Two consecutive years of 6,000 pedestrian deaths is a red flag for all of us in the traffic safety community. These high levels are no longer a blip but, unfortunately, a sustained trend," Adkins said.

"We can't afford to let this be the new normal," Adkins added in a GHSA news release.

Pedestrians now account for about 16 percent of all traffic deaths, compared with 11 percent just a few years ago.

The increase in pedestrian deaths has been accompanied by increased smartphone use nationwide and the legalization of recreational marijuana in several states. Both can impair pedestrian attention and judgment, the report noted.

However, the researchers stopped short of saying that smartphone and marijuana use caused a rise in pedestrian deaths.

Smartphone use rose 236 percent between 2010 and 2016, and the number of smartphone-related emergency room visits are on the rise, according to the GHSA.

The report also said that the seven states and the District of Columbia —where recreational marijuana was made legal between 2012 and 2016—had a collective 16.4 percent increase in pedestrian fatalities for the first half of 2017. Meanwhile, all other states saw a combined 5.8 percent decline.

"This preliminary 2017 data is the first opportunity to look at marijuana impairment as a possible contributing factor in pedestrian deaths, given the recent law changes. It's critical to use this early data to look for potential warning signs," the authors of the report explained.

The report also outlined a number of ways to reduce pedestrian deaths, including: training police to understand and enforce laws meant to protect pedestrians; collaboration between state and federal transportation officials; and policy changes to improve safety for all road users, regardless of travel mode.