CHICAGO -- So why did officer Grace Delgado try to cross the road? To remind motorists that they must stop whenever someone steps off the curb into a crosswalk.

Chicago this year joined a growing number of big cities and small towns that are sending officers into traffic to make motorists pay more attention to pedestrians.

"People, they don't care," said Delgado, whose bright pink baseball hat and orange blouse made her especially tough to miss. "It's 'Get out of my way.' The whole mentality is 'Get out of my way.' "

With Delgado's help, police stopped 78 vehicles in just two hours and told them they'd violated a law that's been on the books for years. That number easily could have been doubled, but officers stopped only drivers who kept moving after Delgado had walked four or five feet into the road.

When they were pulled over, motorists offered all kinds of explanations: One saw the pedestrian in the crosswalk but hadn't heard about the law requiring him to stop. Another knew about the law but didn't see the pedestrian.

Nearly 4,800 pedestrians were killed and 61,000 injured in 2006, according to the most recent statistics compiled by the National Highway Traffic Safety Administration. In Chicago alone, 65 pedestrians have died annually in recent years.

The number of deaths has dropped, but there is concern those numbers could climb again as more vehicles hit the road and the elderly population skyrockets.

"We're beginning to see a healthy desire of older folks to remain active and go out for their daily walks," said Doug Hecox, spokesman for the Federal Highway Administration. "That, along with more cars ... is a recipe for danger."

Some communities already are seeing more walkers because of the slow economy.

"The way gas prices are, people are rediscovering their feet," said Pam Fischer, highway traffic safety director in New Jersey, which recently launched a "Cops in the Crosswalks" program.

In Chicago, most drivers were puzzled to find themselves pulled over.

Roland Sapitula said that stopping was simply not an option. "It was too late for me to get on the brakes," he said.

Louis Ramirez, 84, said he didn't see Delgado -- and he wouldn't have stopped for her if he had. "There's no sign out there," he said. "I [do] not have to stop."

Officers gave motorists a brief lecture about the law, then sent relieved drivers on their way. But police understand that the only thing more effective than a lecture from a police officer is a lecture and a ticket.

"If there's really no threat of getting a ticket for it, you're not going to really pay attention," said officer Chuck Trendle, who was working with Delgado.

In Essex County, N.J., authorities "tried the educational route for years," said Paul Loriquet, spokesman for the prosecutor's office. "But until you hit somebody in the wallet, it doesn't stick."

The threat of a ticket seemed to work in Bellingham, Wash. After the city started a police-decoy program in 2002, the percentage of drivers who yielded to pedestrians rose at least 25 percent -- even at corners where tickets were not being issued.

In St. Petersburg, Fla., the results were even more impressive. The percentage of motorists who yielded to pedestrians jumped from 2 percent in 2003 to 82 percent in 2007, after police began writing tickets, educating the public and installing flashing beacons. Pedestrian crashes dropped 17 percent between 2005 and 2006.

"It starts putting pedestrians on their radar," said Ron Van Houten, a Western Michigan University psychology professor who has studied pedestrian safety and trained officers around the nation, including Chicago.

Police say undercover pedestrians will focus attention on crosswalk safety the same way that giving tickets for seat belt violations convinced more people to buckle up in the 1980s.

"Eventually, people get it," Trendle said.