The Nevada Highway Patrol is seeking help from anyone who may have witnessed a hit-and-run accident on Interstate 80 near Sparks Boulevard.
The accident happened around 8:45 a.m. Wednesday.
The patrol said a white, GMC or Chevrolet sport utility vehicle made an unsafe lane change that forced another vehicle off the freeway.
Officers said Robert Gill, 44, suffered substantial bodily harm when his sedan slammed into a section of guard rail.
Authorities said the suspect vehicle may have damage to the right rear area.