The protesters entered the freeway off Pico Boulevard around 11:20 p.m. CHP urged the crowds to disperse at about 11:45 p.m. after declaring it an unlawful assembly. Officers were able to corral the protesters and cleared the freeway at about 12:15 a.m.
VIDEO: Protesters rally in Leimert Park after Ferguson decision
Earlier in the day, about 100 protesters gathered at Leimert Park as they heard the announcement that Ferguson police Officer Darren Wilson would not be indicted. Making their voices heard, they then took to the streets, briefly shutting down traffic.
"I'm disappointed in America right about now," said Andre Knox. "This is very sad. It's 2014, and I can be killed in the street like its 1849 or something."
The California Highway Patrol stood guard at La Brea Avenue and the 10 Freeway after a handful of protesters headed down the on-ramp trying to get onto the freeway. Officers quickly moved in, but the commotion brought traffic to a crawl.
At one point, they gathered in front of the LAPD's Southwest Station before marching on toward the USC campus.
A splinter group of about 30 people peacefully protesting the grand jury decision lay down on Wilshire Boulevard in Beverly Hills. A few cars got stuck in the midst of the protesters, who appeared to be leaving the vehicles alone.
The group shouted chants of "hands up, don't shoot," the refrain that has become a rallying cry in protests over police killings across the country.
VIDEO: Ferguson protesters lie down at Beverly Hills intersection
The Los Angeles Police Department went on a citywide tactical alert in advance of the announcement of the grand jury's decision, allowing them to keep officers on duty beyond their normal shifts. Firefighters and police officers and about five helicopters followed the progress of the protesters.
The demonstrations remained mostly small and peaceful as law enforcement and religious leaders had encouraged earlier in the day. There were no reports of arrests or violence.
PHOTOS: Rallies held across Los Angeles to protest Ferguson decision
In a statement issued from Asia where he is on a trade mission, Los Angeles Mayor Eric Garcetti said, "Michael Brown's death has ignited deep passions across the nation, and Los Angeles is no exception. Tonight's decision is one that will be heatedly debated -- but we should do so through dialogue and peaceful action. City departments are mobilized to assist in the exercise of peaceful protest."
Los Angeles City Attorney Mike Feuer said he understood the strong feelings surrounding the decision.
"Here in Los Angeles, although we still have much to do, we've come far in building trust between those who enforce our laws and the communities they serve," Feuer said.
The Associated Press and CNS contributed to this report.