Maryland State Trooper Mike Bobenko, 27, aimed his hand - held radar gun down the highway as cars zipped past his hidden position.

The rapidly changing figures on the gun's small screen looked like those on a pocket calculator, and they told Bobenko that people were going 59-57-56-63-61-59-58-56-54-70 . . .

"Red Volvo in the fast lane, 70.' said Bobenko casually into his micro - phone, and a couple of hundred yards down the road another trooper, hearing Bobenko's message blaring from a loudspeaker atop a patrol car, stepped onto the highway and flagged down the Volvo.

When a group of cars is coming by, Bobenko said. 'It's hard for me to know which one is speeding. In a situation like that it could say '70' and I couldn't pull one out.'

With practice, however, Bobenko has learned the quirks of the radar gun, and by glancing back and forth between its screen and the road he can usually pick out the speeding car even when it is mixed in with other cars that are not speeding.

Bobenko and tow other troopers were conducting a classic Maryland police maneuver - the 'stopping team' that is responsible for a large portion of the speeding tickets written on the state's highways.

Bobenko is one of about 50 troopers operating out of the Greenbelt barracks of the state police. The troopers write about 550 speeding tickets a week officials said.

While the police said they don't operate under any quota system, the ticket writing is bread - and - butter work for them, bringing in a good deal of revenue for the state at about $40 a ticket, and providing as one trooper said, the mayor yardstick by which individual trooper performance is evaluated.

Bobenko and the other troopers said they have discretion to choose the speed at which they will start writing tickets.

On the day a reporter visited their stopping team a few miles east off the beltway on 1. 95, they didn't write tickets for any driver going less than about 10 miles over the limit.

Bobenko said that when he drives his ummarked patrol car on area highways he goes at about 45 mph., and,'People go past at 60, which is normal. If they fly by at 70. I'll pull over and pace 'em and charge 'em.'

At the stopping team site many people were angry at being pulled over. The most frequent complaint was that the team was stoppingmostly out - of - state cars.

The troopers said that wasn't so, but in any case explained that they have no way of knowing what state a car is from until alter they have spotted it as a speeding car.

Bobenko said he didn't think people have speeded up much following the general slowdown after the 1973 gasoline crisis.Another trooper said he thinks that slowdown lasted only about a year. "Now people just ignore the 55 mile limit," he said.

The troopers agreed that weekends are the times when most people speed. They said they could sit out there and write tickets all day and night, but that they have other work to do.

Bobenko said that by the time he has stopped a vehicle, he has already made up his mind what the violation is and what ticket he will write.

He only wavered in this once during the day when a truck driver whom he planned to charge with riding too close to a VW's rear pointed out that Bobenko's angle of vision may have thrown off his judgment.

'When in doubt, I give a warning.'

The Radio Shack on Rockville Pike in Rockville, like many other stores, sells radar - detection devices.

'I usually sell all that I have in two weeks,'said salesman David Fox. He added that it is legal to sell the devices, but not in full assembled form.

'The 'Driver Alert Radar Safety Kit' box Blurb said: 'Helps you drive safely in unfamiliar areas. Sounds off before you enter radar traffic zones where conditions may be hazardous or congested. Range of one - half mile gives you time to adjust speed . . . Clips neatly to car's sun visor. Easy to assemble . . .'

Capt. Robert L. Suthard, 45, works out of Culpeper and is responsible for Virginia State Police patrols in the 15 northern countries of the state.

He said that there is 'no question but that speed causes people to be killed' and he is proud that there were fewer killed in auto accidents last year in Virginia - 1, 020 people - than in any year since 1961.

Perhaps people are beginnning to speed again, he said, after the slow - down that followed the imposition of the 55 m. p. h. speed limit.

But he also said there has been in Virginia 'a tremendous increase in the numbers of arrests for speeding.'

He said there were 41, 333 speeding arrests in his 15 counties in 1976, and that his 169 troopers are still writing tickets at about that rate.

'That 's a whole lot of arrests for speeding,' he said

Suthard has been in the department 23 years, and he recounted how his own attitude toward speeding changed.

'I didn't spend much thought on safety and department goals until after I saw some accidents,' he said. 'At first you stop a speeder because this is what you're paid to do. But after two or three years, it's a complete difference because then you're catching the speeder to stop an accident. You go to the scene of an accident, say, and you find one of the drivers was under the influence, and in the car you see a child with broken limbs, or a female with critical injuries . . .'