What is billed as the first mobile phone sidewalk in China was recently installed in Chongqing. The marked sidewalk is an attempt to reduce pedestrian accidents, local media reported. (China Daily via Reuters)

A14-year-old boy was injured when he walked off a six-foot-high bridge into a ditch while talking on his phone. A 23-year-old man was hit by a car while walking down the middle of a road talking on his phone.

The dangers of distracted driving are well known and have sparked new laws, but safety experts are increasingly concerned about a more recent trend: distracted walking.

Pedestrians listening to music, texting, talking or otherwise absorbed in their phones are making themselves more vulnerable by tuning out traffic around them, experts say. While there is little hard data on the problem, safety experts say there is plenty of anecdotal evidence. Many say they think smartphone distractions are at least partly to blame for the number of pedestrian fatalities beginning to rise again in 2010 after years of holding steady or declining slightly.

“We definitely think it’s a problem,” said Jonathan Adkins, executive director of the Governors Highway Safety Association. “I see pedestrians with headphones on looking down at their phones. They can’t see or hear. . . . Anyone who’s out and about sees it every day. We know it’s occurring.”

The problem drew international attention last week, when a city in China created a special sidewalk lane for smartphone users to raise awareness about bumping into other pedestrians. And locally, Montgomery County officials launched a public awareness campaign urging high school students to put down their phones when crossing the street.

Young people walk and use cellphones more than other age groups, experts said. About half of students ages 15 to 19 say they use a cellphone when walking to school, according to the Safe Kids Worldwide advocacy group.

The October 2012 death of 15-year-old Christina Morris-Ward as she crossed a street near Seneca Valley High School in Germantown prompted Montgomery officials to focus on what they call “distracted crossing.” Another student walking behind Christina saw her looking down at her cellphone when she was hit, Christina’s mother said.

Montgomery’s public awareness campaign asks high school students to sign a pledge that they will cross streets safely. Posters in school hallways will show teenagers with black tire tread marks across their faces with slogans such as: “If you text, you’re next” and “Smart phones can make you do stupid things.”

“Christina’s death was a wake-up call for me and my peers, that we had to do more and that distracted crossing was a problem that needed to be addressed,” said Montgomery police Capt. Tom Didone, director of the department’s traffic division.

The number of traffic fatalities overall has been falling nationwide because of safer vehicles, increased seat-belt use and less drunken driving, experts say. But pedestrian deaths began to tick up in 2010. By 2012, pedestrians accounted for 14 percent of U.S. traffic fatalities, up from 11 percent in 2007.

In the Washington region, pedestrian deaths as a percentage of all traffic fatalities grew from 20 percent in 2005 to 24 percent in 2013, according to the Metropolitan Washington Council of Governments. Urban areas tend to have a higher percentage of pedestrian deaths because national figures include rural areas, where there are fewer pedestrians and less traffic.

“As we make progress in almost everything else traffic safety-related, the lack of progress in pedestrian safety is concerning,” said Mike Farrell, the council of governments’ bicycle and pedestrian coordinator.

Allan Williams, a transportation consultant to the governors group and other safety organizations, said data showing the link between cellphone use and pedestrian collisions is limited. He said one study found that distracted walking accounts for about 4 percent of pedestrian injuries.

“It’s not a huge problem,” Williams said, “but it is a problem. We all see it.”

Two recent studies, including one that showed the problem of distracted walking worsening quickly, also raised alarm.

A 2012 study in the journal Injury Prevention found that nearly one-third of pedestrians at 20 high-risk intersections in Seattle were observed listening to music, texting or using a cellphone. Those who texted took almost two seconds, or 18 percent, longer to cross the intersection compared with those who weren’t distracted, the study found. Those who texted also were four times more likely to display at least one “unsafe crossing behavior,” such as ignoring traffic signals or failing to look both ways.

A 2013 Ohio State University study found that the number of injuries treated in 100 emergency rooms nationwide related to pedestrians using cellphones had more than doubled between 2005 and 2010, to more than 1,500. The study found people ages 16 to 25 were most likely to be hit while distracted.

The study included the 14-year-old boy and 23-year-old man mentioned earlier, according to Science Daily.

The number of cellphone-related incidents in any study is conservative, experts say, because pedestrians who are hit are reluctant to tell police they were distracted, and often there are no witnesses to report it.

Safety experts say they’re not trying to cast blame. They note that studies show drivers cause about half of all pedestrian collisions by speeding, running red lights, making illegal turns and blowing through crosswalks. Many also note that more can be done to make roads, particularly wider streets in the suburbs, safer for pedestrians by improving crosswalk markings, installing flashing signals that alert drivers to pedestrians in the road, lowering speed limits, and building raised “refuge island” medians where pedestrians can stop halfway.

But persuading more people to put their heads up and their cellphones down would be a relatively quick and inexpensive way to reduce at least some pedestrian collisions, experts say. Doing so also would curb a trend that is expected to continue as more people become increasingly dependent on smartphones.

“This is not about placing blame — it’s not about blaming pedestrians or blaming drivers,” Adkins said. “It’s about personal responsibility.”