The San Francisco Bay Area is grappling with a mounting problem of show-off, threatening dirt bikers and All Terrain Vehicles on local highways.

In the latest incident, some 30 people on dirt bikes, ATVs and motorcycles popped wheelies, weaved through lanes and veered dangerously close to drivers on the Bay Bridge from San Francisco to Oakland Sunday, police said. Days earlier, a gang of bikers yanked an Uber driver out of his car on San Francisco’s Highway 101 and beat him so badly that they broke his leg.

This evening we caught a group of ATVs and dirt bikes that were riding around on the freeway. #Busted https://t.co/hRWxhrYNSN pic.twitter.com/oIfLLaP8IS — CHP Oakland (@CHPoakland) March 20, 2017

The wild California highway displays of reckless driving are part of biker “sideshows.” The ATVs are not legally allowed on the highways, the Bay Bridge, or regular streets, other than to cross them to get off road.

Drivers are often hard to catch or track because they remove their license plates, authorities say. It’s often dangerous for police in a high-traffic area to chase and apprehend them. When officers do try to catch them, the bikers slip down sidewalks, between homes and even down steps.

In the Bay Bridge incident a California Highway Patrol spotter plane tracked the crew from the sky, authorities said Monday. Most of the drivers managed to flee police cars on the Oakland side of the bridge. Police arrested one female driver, detained others, and confiscated four vehicles, the CHP said in a statement. Police are examining video taken of the crew from the spotter plane to identify others.

“The riders had been acting aggressively towards other motorists, and were riding recklessly,” the CHP said in its statement.

Investigators were trying to determine whether there were any links between the attack on the Uber driver and this crew.

Vu Williams of the Highway Patrol told KCBS-TV that there were similarities between the incidents. Both cases featured ATVs with missing license plates and drivers pulling similar stunts — on local highways.

“We are going to review our aircraft’s video tape. They could face possible prosecution later,” said CHP Officer Sean Wilkenfeld. “We want to remind them don’t come to Oakland and cause shenanigans like this, because we are going to take your vehicle and you are going to go to jail.”

Stanley Roberts has tracked both car and biker sideshows for years as a reporter for San Francisco’s KRON4-TV and creator of a regular feature for the station called “People Behaving Badly.”

He calls the drivers a “bunch of idiots doing donuts and terrorizing neighborhoods.” The sideshow capital of the Bay Area has been Oakland, one of the main centers of the events in the nation.

Usually drivers in both car and dirt bike sideshows stick to neighborhoods and area streets, he told The Huffington Post. Now the bikers are hitting the highways in San Francisco, and he hears they’re about to crank up the action this summer. The beating on Highway 101 was a level of violence in a sideshow that he had never seen before. The bikers are “bold, brazen and don’t give a damn,” he added.

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