More than 800 pedestrians were killed trying to cross a freeway in 2018, which represents a significant increase from a decade earlier, according to new research from the Insurance Institute for Highway Safety.

Oftentimes the pedestrians are homeless people who are struck on freeways in urban areas, the research found.

"Our findings suggest that localities with residential communities across the freeway from shopping centers, bus stations or entertainment districts should consider physical barriers that prevent pedestrians from crossing — especially if the commercial centers include bars or liquor stores," said Jessica Cicchino, the institute's vice president for research.

Across the country, pedestrian fatalities increased 53% from 2009 to 2018 and now account for 17% of traffic deaths. Pedestrian fatalities on interstates and other high-speed controlled-access roads increased 60% over that time. More than 800 pedestrians have been killed on such roadways each year from 2015.

The research revealed that California had the largest number of pedestrians killed crossing interstates and freeways.

Most of the 2,518 pedestrian fatalities from 2015 to 2018 occured in urban areas, at night, and in the dark, according to the institute. More than half took place in locations where the speed limit was 65 miles per hour or higher.

"Darkness and speed often come into play in pedestrian crashes, but these factors are exaggerated on interstates and freeways," said Jin Wang, the lead author of the study. "That suggests better-lit roadways and better headlights could make a difference."