A Queens Sanitation worker who took matters — and car keys — into his own hands, was busted Saturday when he triggered a chain reaction crash when he tried to move a van that was in his way, police said.

James L. McGuiness, 50, was collecting garbage on Hampton Street near Elmhurst Avenue in Flushing around 11:30 a.m. when he encountered an unoccupied 2003 Ford van — with the keys still in the ignition, cops said.

McGuiness, 50, hopped inside and turned the keys, but as soon as he backed up, he ended up hitting the Acura sedan behind him — which then struck a Honda SUV parked behind it, cops said.

A 29-year-old man — who said he owned all three victimized vehicles — heard the ruckus and called cops.

McGuiness was charged with unauthorized use of a vehicle, cops said.