Reported by Dr. Sam Li:

Pedestrians who text are four times less likely to look before crossing the street, cross at designated areas or obey traffic lights, according to a new study that highlights the hazards of mobile technology.

In monitoring 20 of Seattle's busiest intersections, researchers from the University of Washington found that texting pedestrians also took an average of two seconds longer to cross the road.

"Mobile devices have added to efficiency, but also follow us home and intrude into areas where concentration is required, like crossing a busy intersection," said Dr. Beth Ebel, director of the University of Washington's Harborview Injury Prevention & Research Center in Seattle and lead author of the study published Wednesday in the journal Injury Prevention.

Previous studies have found that pedestrians are less cautious and more likely to engage in "risky crossing behavior" when wearing headphones or talking on cellphones. And a 2010 study found pedestrians using cellphones took longer to cross the street.

With smartphone use on the rise, Ebel called for new policies to limit the risk of pedestrian injuries.

"Ultimately a shift in normative attitudes about pedestrian behavior, similar to efforts around drunk-driving, will be important to limit the risk of mobile device use," she said. "I also hope parents will consider specifically discussing our findings with their kids, and will also consider the impact of their role-modeling on what children perceive as competent adult behavior. As parents, what we say matters much less than what we do."