Police were called by a witness from a highway in the city of Denver, Colorado, following the attack on Friday.
By Lucia Binding, news reporter
An Uber driver has been arrested in the US on suspicion of first-degree murder in the shooting of one of his passengers.
Michael Andre Hancock, 29, is accused of killing Hyun Kim, 45, during an incident in the early hours of Friday morning in Denver, Colorado.
Police were called by a witness shortly before 3am from a highway in the city, reporting that "an Uber driver… said his ride tried to attack him and the driver shot him," an officer stated in a court document.
Mr Kim was lying fatally wounded on the front passenger seat floor of the Sedan vehicle, which had stopped on a ramp, and officers failed to revive him.
Police arrested the driver at the scene.
They allegedly found a semi-automatic pistol in his waistband and later recovered 10 spent .40-caliber cartridges plus a blood trail on the shoulder of the highway.
The Denver Medical Examiner's Office identified the victim as Mr Kim.
US media is reporting that he is originally from South Korea but had been living near the city.
An Uber spokesman said of the incident: "We are deeply troubled by the events in Denver today," according to local media.
The ridesharing company has been linked to similar controversies in the past.
Police in Michigan charged an Uber driver with six counts of murder after he reportedly went on a killing spree two years ago through the city of Kalamazoo.
The driver, Jason Dalton, allegedly confessed.