In Finnigan v. Blanco County, 670 S.W.2d 313 (Tex.App.--Austin 1984, no writ), a deputy sheriff parked his patrol car near the jail's exercise yard and left the motor running while he went inside.
The deputy knew the jail's only prisoner had access to the exercise yard. The prisoner escaped, got into the car, and fled the area.
The get-away vehicle was then involved in a fatal collision after the officers gave chase.
The court of appeals held that the use or operation of a motor-driven vehicle involves the transportation of a person from one place to another and necessarily includes stopping the vehicle and leaving the motor running. Id. at 316.