The National Highway Traffic Safe­ty Administration (NHTSA) reported that in recent observations of about 54,000 drivers stopped for traffic signals in 11 cities, only 19.8-percent of those driving 1977-model cars had their seat belts fastened. This com­pared with 21.1-percent of persons driving 1976-model cars in the same survey, 24.2-percent of those driving 1975 models and 29.2-percent of those driving 1974 models.

The agency said the trend toward declining usage is directly opposed to traditional trends in seat-belt usage. In the past, seat belt use has been greater by drivers and passengers of late-model rather than older-model cars. The overall belt-usage rate shown in the survey was about 20-percent. That figure includes the considerably lower averages for 1964-1971 models. Similar studies showed overall rates of 25-percent three years ago and 22-percent two years ago.

Inflated figures for 1974 and 1975 model years were attributed to "inter­lock" systems in which cars were equipped with devices to prevent them from being started unless the seat belts were buckled. The system was scrapped later by Congress. Many interlock systems have been disconnected.

The NHTSA says some new belt designs tend to discourage belt use and added that the "progressively decreas­ing" usage rates in the 1975-77 period indicate that auto makers are installing belt systems that are "less convenient and less comfortable to use."

Meanwhile, NHTSA released a re­port showing a dramatic reduction in highway deaths in cars equipped with automatic crash protection. The latest survey by the department's Fatal Accident Reporting System (FARS) shows that the death rate for Deluxe Model Volkswagen Rabbits equipped with automatic shoulder belts is about one-third the rate for other VW Rab­bits equipped with ordinary seat belts. The automatic shoulder belt goes into place when the door is closed.

There are approximately 79,000 Rabbits with automatic crash protec­tion on the nation's highways and these cars have traveled about 1.2-billion miles with only six fatalities. This compares with 300,000 Rabbits equipped with regular seat belts that have traveled 4.8-billion miles on the nation's highways with 81 fatalities.