The man sitting on the tracks near County Road 427 and North Street challenged the subcontractor, then pulled a gun and tried to rob him, said Heather Smith, a sheriff's spokeswoman.
The contractor pushed the gun away, but the man fired, striking the contractor in his right side, Smith said. He was taken to Orlando Regional Medical Center with injuries not thought to be life-threatening.
The gunman ran away.
No names were released.
Sunrail is Central Florida's planned commuter-rail system.
firstname.lastname@example.org or 407-540-5981