The first day of what is supposed to be a nationwide shutdown by independent truck drivers ended with one person shot and killed, rumors and reports of other shootings, much confusion and no measurable impact on shipment of goods, according to industry and federal officials.

The unidentified truck driver was killed just before midnight outside Newton Grove, N.C., police told the Associated Press. The trucker had been driving along U.S. 701, and police at the scene said a high-powered rifle may have been used. Details of the shooting were not immediately available.

In Brigham City, Utah, another driver was shot in the chest by a sniper yesterday afternoon. Authorities said Howard N. Adams, 45, of Riverside, Calif., was unloading his rig at the time. He was undergoing surgery last night but his condition had not been determined, the AP said.

Transportation Secretary Drew Lewis estimated that about one-fifth of the nation's independent truckers were taking the day off.

"As far as the truckers' strike is concerned," Lewis told reporters, "the anticipated impact has not been felt . . . . That doesn't mean we're taking it lightly."

Mike Parkhurst, president of the Independent Truckers Association and the man who called the shutdown to protest increases in federal taxes on truck use and fuel, claimed that 50,000 to 75,000 independent truckers of an estimated 100,000 were parking their rigs yesterday.

Parkhurst repeated his prediction that the shutdown will be 98 percent effective, but said the effects will not be felt for four or five days.

Independent truckers, who own and operate their rigs, represent about one-third of long-haul drivers but carry much of the nation's fresh produce and household goods.

Many have said they would adopt a wait-and-see attitude and that, if there is violence, they will wait it out.

Gunshots were fired at 11 tractor-trailer rigs in incidents in nine states, the AP reported last night. But some incidents could not be verified.

The Mississippi Highway Patrol told the AP of two shooting incidents in that state. One involved driver Robert Wells of Summit, Miss., who said he returned the fire when one of three men in a car started shooting at his truck near Crystal Springs.

Police said the truck was hit three times on the left door, once on the left window and twice on the back of the cab.

At Jarrell's Truck Plaza in Ashland, Va., shift supervisor Dave Cadora said, "A lot of that stuff comes in on the CB radio and escalates every time it's retold."

At the same time, he said, business was off a bit "even though the strike's not going to start officially until midnight tonight."

Cadora's statement pointed to one of the uncertainities: many truckers were unsure whether the shutdown was called for midnight Sunday, as Parkhurst's group said, or for midnight yesterday.

Susan Portney, a spokesman for Giant Food here, said "we haven't had any problems" obtaining produce, and federal officials reported similar statements in checks with other shippers.

Portney said Giant had arranged to ship produce by piggyback--truck trailers carried on rail flatcars.

That type of diversion from independent truckers is what many experts predicted would happen at a time when, because of the recession, there is an estimated 30 to 40 percent excess capacity in the trucking business.

Neither the Teamsters union, which represents most non-independent drivers, nor the American Trucking Associations, which represents most major trucking firms, has supported a shutdown.

Parkhurst said he based his estimate of 98 percent effectiveness on the fact that he had personally talked last week to 9,000 truckers in meetings throughout the Northeast and Midwest.

Lewis defended the new taxes on trucks as "equitable," restating the position he took before Congress that trucks tear up the roads and should pay for the damage.

Lewis said, however, that federal officials would be willing to consider two issues Parkhurst has raised:

* An adjustment in truck taxes, with more emphasis on the diesel fuel tax--which goes from 4 cents to 9 cents per gallon April 1--and less on the heavy vehicle use tax, which will increase from $240 to $1,900 for the largest trucks by 1986.

* Standardization and reduction in the multitude of forms, licenses and permits truckers must obtain from each state they traverse. That, Lewis said, is a "legitimate concern," but such a correction would require federal preemption of many state laws.