Houston police said the pedestrian was not in a crosswalk and was running across the mainlanes when he was hit in the 5800 block of Westheimer Road near Fountain View Drive shortly before 11 p.m. Monday.
"Behind me, there is no intersection close to the street that's legal for pedestrians to cross. There is a signal light quite a distance down in both directions," Sgt. David Rose said.
The driver immediately stopped and tried to help the man until paramedics arrived, HPD said. He was pronounced dead at the scene.
Investigators said the driver did not show any signs of impairment.
So far, police said it's unclear why the man was running across the street in the first place. He was reportedly alone.
Investigators were looking for surveillance video of the crash at nearby businesses.
"It's imperative. You do not have the right of way to cross the road anywhere else but a crosswalk, and most of the crosswalks on Westheimer are at intersections," Rose said. "I know it sometimes is annoying, when you think you can just cross the road and take a minute, but if you take a few minutes to go down to the next intersection where the lights stop the traffic, it's extremely safe to do that versus just running in the street."