New Jersey cops finally nabbed their Public Enemy No. 2 — a man accused of dumping dirty diapers along several area roadways for the past year.

The alleged serial diaper-dumper, 68-year-old William Friedman, was caught over the weekend unleashing his last roadside load.

Franklin Township Police Officer Garrett Moretti had been conducting a patrol around 3:15 a.m. Sunday in the area of Route 47 and Route 40 when he saw a box truck “drop a load of soiled diapers in the roadway,” police said.

The cop conducted a traffic stop and took Friedman into custody.

Friedman, a Newfield resident, then copped to investigators that he had been dropping poop-filled diapers at different locations in Franklin Township over the last year in what he claimed to be a “joke.”

He also allegedly told cops that the diapers were from his grandson.

Police called Friedman’s purported joke “no laughing matter,” saying that back on June 24, a motorcyclist was involved in a serious crash caused by the “motorcycle sliding on the plastic bag of soiled diapers that was left in the roadway.”

The motorcyclist in that case suffered minor injuries and his bike was totaled.

Meanwhile, Friedman was charged with interference with transportation and was slapped with numerous traffic tickets and fines, according to cops.

“We would like to congratulate Ofc. Moretti on a job well done,” the Franklin Township Police Department wrote in a post on Facebook announcing Friedman’s arrest. “It was a sh*#ty job, but someone had to do it!!!!!”

With Post wires