Joseph Laiosa, 38, is accused of threatening the other motorist with the firearm on the southbound side of the freeway about 12:20 p.m. Tuesday, shortly after they got into a dispute over lane positions on a Manchester Avenue on-ramp in Encinitas, according to the California Highway Patrol.
The suspect remained at large until late Thursday morning, when sheriff's deputies located him and notified CHP personnel, who took him into custody, said Officer Hunter Gerber.
Laiosa was booked into a detention facility on suspicion of illegally brandishing a weapon and possession of fentanyl, authorities said.
The disturbing encounter was captured on video from multiple angles by the alleged victim's Tesla, which is equipped with several cameras.
City News Service contributed to this report.