Motorists Tuesday evening were startled to see a woman running along the fog line of the Highway 120 Bypass.
The woman was spotted running against traffic along the eastbound lanes of the freeway shortly after 7 p.m.
Witnesses said she was frantically sprinting while waving her arms repeatedly at the oncoming traffic. That prompted motorists to hit their brakes and slow down causing traffic to start backing up.
Manteca Police patrolman Danny Chestnut was the first officer to come up on the woman.
Chestnut parked his patrol unit on the shoulder midway between Airport Way and Union Road and then took after the woman on foot.
He was able to chase the woman down and detain her and before cuffing her for her own safety.
One motorist said the woman appeared to be uncooperative with the officer.
Minutes earlier, police had received 9-1-1 calls about a woman with braids running in and out of traffic on South Airport Way at Atherton Drive just south of the 120 Bypass. Callers said it seemed like the woman was trying to intentionally run into their vehicles.
Officers were responding to the Airport Way and Atherton Drive location when dispatch got a 9-1-1 call about a woman running down the freeway.
There was no information available as of press time if any charges were being filed against the woman or if she was still being detained.