Sgt. T. R. Thomas of the North Carolina Highway Patrol, said the case was typical of others he had seen: The man was returning home after midnight from a tavern and, according to witnesses, was highly inebriated. ''What probably happens is these people get drunk and lay down on the road because of the warmth,'' said Sergeant Thomas.

That is precisely Dr. Harris's hypothesis: that people in a drunken stupor, like possums, are drawn to the highway because the macadam surface retains heat from the day. Although the incidents most commonly occur in summer, Dr. Harris said people who are drunk lose so much heat that they become chilled while walking home in the cool of the night.

Dr. Harris presented the survey on lying-in-the-road deaths at the annual meeting of the American Academy of Forensic Sciences in New Orleans in February. He was assisted by researchers from the University of North Carolina Highway Safety Research Center and the state's Office of the Chief Medical Examiner. #70% on Rural Roads The study excluded deaths that might have been suicides or that involved victims who were thrown onto the pavement in vehicle accidents and then run over.

About half the victims in the 136 fatalties studied were black and half were white. All but a few were men, and virtually all were intoxicated, often having blood alcohol levels far above the threshold used to define drunken driving.

In fact, investigation showed that many of the victims had already had their driver's licenses revoked for driving under the influence of alcohol, which suggested a corollary question to Dr. Harris: ''Are we taking the drunken drivers off the road only to turn them into drunken pedestrians?''

Seventy percent of the accidents occurred in rural areas, usually along two-lane county roads after dark and on weekends. There were 144 vehicles involved in the 136 deaths, suggesting that some victims were run over more than once. About four out of every five drivers stopped after running over the victims, Dr. Harris said.

Dr. Harris's study brought some sharp reactions. In an editorial, ''Liquored Up, Smashed Flat,'' The Wilmington Star-News in North Carolina took note of the fact that the incidence of people killed while lying in the road was not only higher in the rural South than in the urban North, but also that North Carolina appeared to be one of the leading states.