For Rita Asen, a retired social worker who broke her hip two years ago and walks gingerly with a cane, crossing West End Avenue is not quite as challenging as braving the rapids of the Colorado River. On the other hand, the Colorado River doesn't have careening cars and deliverymen rushing about on bikes.

"You have to be very careful," said Mrs. Asen, who has lived for more than three decades in Lincoln-Amsterdam House on West End Avenue near 65th Street. "You just don't know when the light is going to change and you can be stranded in the street."

Mrs. Asen is one of more than 200 elderly residents of the Upper West Side who took part in a yearlong study about pedestrian safety in their neighborhood, where 13 percent of the population is over 65. Armed with maps and disposable cameras, a small armada of those men and women were dispatched to document specific dangers on their streets.

The study, which covered about 200 blocks from 45th Street to 97th Street, was conducted by the advocacy group Transportation Alternatives and Assemblywoman Linda Rosenthal, whose district covers the survey area. A 25-page report was released in November, and this year the city announced a project to make walking safer for the elderly.

The project will be conducted in 25 neighborhoods, including the Upper West Side, over the next two years. A spokesman for the Transportation Department, Ted Timbers, said the city would consider incorporating measures recommended in the study, which include extending the crossing times at crosswalks, adding traffic medians and extending curbs.

In calling for changes, Ms. Rosenthal noted that older people, if they are afraid to venture outside, run a greater risk of becoming isolated, malnourished and depressed.

"For seniors who feel trapped in their apartments because they're afraid of cars and buses, the picture has to change," she said.