The deadly collision was reported about 5 a.m. on the westbound 10 Freeway connector to the northbound 110 Freeway. California Highway Patrol officials said the motorcyclist, who has not been identified, was thrown off the transition road and landed onto Venice Boulevard, just below it.
Several lanes in the area of the crash were closed for about two hours, causing a major back-up to an already congested area of downtown during the morning commute. Washington Boulevard was being used as alternate for commuters heading to downtown L.A.
By 7 a.m., CHP officials said all lanes were back open.
The cause of the crash was under investigation.