(Eugene, OR)  --  Police haven't yet released the name of a Springfield man who died after jumping from an Interstate 5 overpass near Eugene.  Officials say the 21-year-old man got off his bicycle around 12:35 Saturday afternoon on the Glenwood Boulevard overpass and climbed an eight-foot fence.  Police say after falling about 25 feet onto the right northbound lane of I-5, the man may have been struck by a white Ford pickup truck that continued north.  Authorities are looking for that truck.