The fog-related freeway pileup in North Salt Lake last January that killed three people is one of several accidents that has prompted the National Transportation Safety Board to schedule a hearing this week on how government and drivers react to fog.

Meeting in Knoxville, Tenn., on Wednesday and Thursday, the board will discuss ways to reduce fog-related highway accidents."The Safety Board has been concerned about fog accidents since 1967 and has investigated at least 11 such occurrences," said board chairman James Kolstad. "(The hearing) will provide the board with the flexibility to focus on national aspects of the fog problem rather than only on-site specific accidents matters."

Four multiple-vehicle accidents in Utah, California and Tennessee in the past year sparked the hearing. The accidents involved 238 vehicles, killed 21 people and injured 90.

The Utah accident occurred Jan. 2 in morning rush-hour traffic on a 2-mile stretch of I-215 in North Salt Lake. The 52-vehicle pileup killed three people and injured 17.

State transportation officials said motorists driving too fast in foggy conditions, then abruptly slowing down when visibility became zero, caused the chain-reaction accident.

Among the items the board plans to discuss in countering foggy driving conditions:

- Adequacy of federal and state policies and procedures dealing with fog.

- High-tech fog-sensing and warning devices.

- Heavy truck and small automobile traffic together in fog conditions.

- Driver perception and reaction to fog conditions.