Officers say it happened near Van Ness and Lansing when the officer was trying to clear out traffic. The officer's lights and siren on his motorcycle were both on.
A Ford truck going west on Lansing went through the intersection, leading to the collision.
The officer was ejected from the motorcycle and suffered minor injuries.
Investigators do not know if the driver saw the officer before the collision. The driver stayed on scene and did not suffer any injuries.
The intersection at Van Ness and Lansing has reopened.