Ramirez, a Redwood City resident, was crossing east on Middlefield Road near Dumbarton Avenue shortly after 2 a.m. when he was struck by a 2013 Nissan driving north, CHP Officer Art Montiel said.
Ramirez was pronounced dead at the scene, Montiel said.
The driver of the Nissan, identified as a 32-year-old man from Rochester, N.Y., stayed at the scene and was cooperative with investigators, Montiel said.
The driver did not appear to be under the influence of any substance, according to Montiel.
But police believe the victim, Ramirez, was under the influence of alcohol at the time of the collision, Montiel said.
All lanes of Middlefield Road at Pacific Avenue were closed for more than two hours.
The collision remains under investigation and any witnesses are asked to call CHP Officer T.J. Taylor at (650) 369-6261.