Los Angeles leaders on Wednesday unveiled a billboard campaign to help cut down on hit-and-run crashes.
The billboards will be put up around the city, asking drivers to "stick around" after a crash.
The campaign comes at a time when hit-and-run crashes make up nearly 48 percent of all car collisions, officials said. In the rest of the nation, drivers only leave the scene 11 percent of the time.
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Pamela Strong, whose brother Paul was run over almost a year ago, hopes the campaign will raise awareness of the good potential witnesses can do in bringing closure to victims' families.
In her brother's case, a witness came forward about her brother's death and police were able to catch the man who did it.
"It meant the entire world to me," she said. "The victim's next of kin, and his only kin."
The campaign is designed to push LA's hit-and-run numbers down.
"When you leave somebody at the side of the road, like a wounded animal, you are a coward and you are a criminal," said City Councilman Mitchell Englander.
Hit-and-run crimes are a growing problem in many urban areas, where pedestrians,
cyclists, and motorists all share space, LA city officials said.
The number of hit-and-run collisions has increased in California over the last few years, despite efforts by law enforcement agencies to curtail it, according to Gerry F. Miller, the Chief Legislative Analyst in a 2014 report to a city committee studying the issue.
Miller said the crimes are difficult to solve, as there is often little or no evidence.
"Even when there is a description of a vehicle, the perpetrator has often fled long before law enforcement is able to disseminate information on the incident to the public," Miller said in his report.
Some law enforcement agencies and pedestrian and cycling advocates have called for stiffer penalties and new laws to deter hit-and-runs.
California Gov. Jerry Brown signed a bill by Assemblyman Mike Gatto, D-Los Angeles, that would establish a "Yellow Alert" be activated following a hit-and-run collision that results in a fatality or serious injury. Police agencies can request the alerts beginning in January.