A dog not even one-eighth the size of a car managed to bring evening commute traffic to a halt on a multi-lane California highway Monday afternoon.

Drivers on Highway 50 near Sacramento stopped to avoid hitting the dog and some even gave chase on foot after the dog ran the equivalent of roughly 20 blocks along the highway.

"I saw cars pulling over and thought there was a collision," California Highway Patrol (CHP) Officer Michael Bradley told ABCNews.com today. "Then a motorist said, 'There's a dog running on the freeway.'"

Bradley was patrolling a construction site on the freeway's eastbound lanes when he saw the dog start to run in the opposite direction before turning around.

"As we shut down traffic trying to catch him, he turned back eastbound and jumped over a railing, and probably landed 20 to 30 feet down onto the surface street below," Bradley said. "Then, we saw him running northbound into the city."

Though the chase, which Bradley estimated lasted about seven to 10 minutes, was done to protect the dog, some motorists' zeal for capturing "man's best friend" resulted in even more danger, and headaches, on the road.

"One motorist tried to run after him and he left his truck in the middle of the traffic lane," Bradley said. "We had to tell him to come back to move his truck off the road."

No one was hurt in the chase. The fate of the runaway dog was unknown.