The man, 47-year-old John Soopikian, was involved in a crash with a 37-year-old San Ramon woman on southbound I-680 at 9:30 a.m. when they exited the freeway to exchange information, Fremont police said.
The two stopped on the north curb of Washington Boulevard, just off the Washington off-ramp, and were exchanging information on the sidewalk.
As this happened, a 2004 Buick LeSabre, driven by an 83-year-old Fremont man, curbed the sidewalk and struck Soopikian, police said.
The car continued down an embankment, coming to a rest against a chain-link fence and a tree.
Police found Soopikian pinned underneath the car. The 83-year-old man was found in the car but unresponsive.
Both were transported to San Jose Regional Trauma Center. Soopikian was pronounced dead at the hospital, police said.
The condition of the 83-year-old man was admitted but his condition has not been released.
Drugs or alcohol did not seem to be a factor, and the crash is still under investigation, police said.