Marked crosswalks are designed to protect pedestrians, but they appear to be doing just the opposite for older adults at one type of intersection.

Older pedestrians are 3.6 times more likely to be hit if the crosswalk is at an intersection with no stop sign or traffic light, new research shows.

"Pedestrians should not get a false sense of security where there is a marked crosswalk. It actually would be safer not to have a crosswalk if there is no signal," said Dr. Thomas Koepsell, director of a study at the Harborview Injury Preven-tion and Research Center at the University of Washington in Seattle, Wash., whose research was published recently in the Journal of the American Medical Association.

Koepsell, a professor of epidemiology, said many older adults may have slower walking times and are less agile to dodge an oncoming vehicle. They should be especially cautious when crossing the street at high-risk locations, according to Koepsell and his colleagues at UW, UCLA and the Centers for Disease Control and Preven-tion.

Older pedestrians, especially, would be much safer crossing where there is a stop sign or signal, the researchers said.

Pedestrian-vehicle accidents killed 4,739 people in the United States in 2000, and one-fifth of them were people age 65 and older. Older adults have the highest pedestrian fatality rate.

The researchers studied 282 sites where a pedestrian age 65 or older had been struck, from 1995 to 1999, in Seattle, Tacoma, Everett and Bellevue in Washington state, and West Los Angeles and Long Beach, Calif. They matched and compared them with 564 nearby sites and allowed for variations in pedestrian and vehicle flow, crossing length and signals.

Koepsell said the study results should serve as a warning for older pedestrians and provide data for traffic engineers deciding how to place crosswalk marking.