The NYPD has made no arrests in the cases of four hit-and-runs since December — despite claiming to know the identities of two of the drivers.

The driver of a Department of Sanitation sand spreader struck a pedestrian in the Bronx on Jan. 8 while making a turn onto Willis Avenue, then fled. The driver was suspended by the DSNY and was questioned by the NYPD, but has not been arrested, according to a police spokesman.

Joseph Chiam, a 72 year old Cyclist from the East Village, was struck by a hit-and-run oil truck making a left turn on Feb. 4 while riding on Eighth Avenue near 45th Street. The driver fled. Police say they have identified the driver but have made no arrests.

“We’re working with District Attorneys in both boroughs,” a police spokesman told Streetsblog.

Other hit-and-run cases from the past two months remain unsolved. The driver of the white truck that killed cyclist MD Rajon in East New York on Dec. 14 remains at large, as does the driver who killed 27-year-old pedestrian Fernando Trejo on Brooklyn's deadly Third Avenue on Jan. 14.

Streetsblog has long covered the failure of the NYPD to arrest hit-and-run drivers, who are often the only witnesses to their crimes. When victims do survive being struck, they often face a second ordeal of having to find their own evidence or file Freedom of Information Law requests to get their own police reports.

"The perpetrator can simply say, 'Iit wasn’t me,' and police will not file charges, even if they identify the vehicle," reporter Ben Fried wrote last year. "This high threshold of proof helps explain why police investigators put so little effort into apprehending hit-and-run drivers."

The New York Times has also examined the NYPD's failure to arrest killer drivers, even when their identities are known.

Pedestrian advocates say they are angered but unsurprised by the latest lack of arrests.

“It’s outrageous,” said Marco Conner, interim co-director at Transportation Alternatives. “The NYPD sees traffic violence as a lesser form of violence.”

But it's nothing new. Conner said the NYPD Crash Investigations Squad has the ability to thoroughly investigate these hit-and-run cases, but that they only thoroughly investigate a fraction of them and will only give a case extra attention when it generates public outrage.

Anyone with information regarding these crashes is encouraged to call 800-577-7177 (TIPS).