They wanted the highway to themselves — just to show off.
The bikers who viciously beat a Manhattan driver in front of his horrified family first boxed him in to try to take over the West Side Highway to do reckless tricks, law-enforcement sources told The Post.
The bikers had already blocked off some highway entrances to keep drivers from getting onto the stretch near West 125th Street at around 1:30 p.m. Sunday, sources said.
But the victim, 33-year-old Columbia grad and Internet honcho Alexian Lien, accidentally bumped his Range Rover into the bike in front of him — sparking a wild, videotaped chase and his eventual beating.
Two bikers are in custody.
Christopher Cruz, 28, of Passaic, NJ, was charged with reckless endangerment for bumping Lien’s black Range Rover SUV.
Allen Edwards, 43, of Queens, who allegedly smashed Lien’s rear driver’s-side window, was also charged with menacing and reckless endangerment.
“[Edwards] told investigators he felt really bad about what happened,’’ one source said.
The biker who filmed the confrontation with his helmet cam is still being sought.
Another biker, Edwin “Jay’’ Mieses, 26, remained hospitalized in a coma, possibly paralyzed for life after being run over as Lien tried to flee.
Additional reporting by Jamie Schram and Kate Sheehy