But Monday night, their offense went beyond noise or traffic violations.
When a motorist encountered a group of teens and young men on dirt bikes and ATVs blocking Hurley Street near Ontario, he honked and shouted at them to move.
Instead, the punks threw things at his 1993 Mercury Sable and chased him until he crashed into several parked cars. When the panicked motorist fled his wrecked car on foot, the ATV drivers ran him down, repeatedly rolling over his fallen body until he stopped moving, witnesses told police.
"All I heard was VROOM VROOM BOOM!" Flores said. "I was in the kitchen. By the time I got to the door, it was done."
The 29-year-old victim, whom police did not identify, remained in critical condition at Temple University Hospital yesterday.
As police canvassed the neighborhood seeking witnesses and suspects yesterday morning, some complained that the incident was a tragedy waiting to happen.
"They have no respect for the law," Flores said, adding that he often saw ATV riders drinking alcohol, doing drugs and painting graffiti near the McVeigh Recreation Center.
Stewart said that he often sees ATV riders doing wheelies in the street, roaring down the rec center's steps and doing doughnuts on the rec center's grassy field.
Neighbors complained that many ATV and dirt-bike drivers use Ontario Street and surrounding side roads to avoid the congestion and possible notice from police on busier nearby streets like Allegheny Avenue.
Besides racing, many of them "challenge" other motorists by blocking streets, cutting off other vehicles and getting unnervingly close, neighbors said.
And while some of the drivers appeared to be teens, others "ain't no babies," Flores said. "They 18, 19. They want to do what they want to do."
Police spokesman Lt. Frank Vanore acknowledged that ATVs are a problem on many city streets, including in Kensington.
But the Police Department's strict pursuit policy can stymie officers' efforts to collar ATV offenders. The policy permits pursuits only if the officer believes it will prevent someone's death or serious injury; or if a pursuit is necessary to nab someone who committed, or tried to commit, a violent felony, or who possesses a deadly weapon.
"These ATVs are not legal [to operate] on the street," Vanore said. "When we are safely able to stop them, we confiscate them. The problem is safely stopping them. A lot of these things take off, and they can go down narrow alleys, on sidewalks, the wrong way on streets. The only thing pursuing them does is create more of a hazard."
Statistics on how many ATVs the Police Department confiscates yearly weren't immediately available.
City Councilman Frank DiCicco, who held public hearings about five years ago on illegal ATVs, agreed that they remain a problem on city streets.
Parents shouldn't permit teens to buy or use ATVs, mini-motorcycles or dirt bikes, DiCicco said. Dealers should be more aggressive in ensuring that ATV buyers are old enough to buy them and are properly insured, he added.
And, DiCicco said, police should "make their life a little bit miserable - ticket them if they're parked on the sidewalk. Radio ahead to stop them if you can't pursue them. We just can't continue to allow the laws to be broken without any penalties being imposed."
Tipsters with information about the Ontario Street incident can call detectives at 215-686- 3243.